Towards Sustainable Solvent-Based Affinity Separations

This dissertation will focus on creating specific separation processes, called Solvent-based Affinity Processes, in which not only the energy requirements will be lower than current state-of-the-art processes, but also evaluate the use of sustainable solvents which can be produced from sustainable resources. The search towards alternative, better functioning, solvents is therefore not a new research topic and has been done for many decades. In Chapter 3, we compiled and visualized a comprehensive database of infinite diluted activity coefficients (γ∞) which is a highly specific parameter that describes interactions between the solute and solvent. Chapter 4 describes a methodology using the 3-component Margules equation to extend the applicability of the γ∞ towards realistic solvent to feed ratios, or in other words, finite concentrations. Chapter 5 assesses the possibility of predicting these γ∞ by using eight theoretical models, while Chapter 6 attempts to correlate γ from solely heat of mixing experiments via thermodynamic models which allows for the prediction of isobaric vapor-liquid equilibria. In Chapters 7 and 8, we screen biobased solvents, for the extractive distillation of resp. apolar and polar mixtures, while Chapter 9 extends this investigation into liquid-liquid extractions using a promising biobased solvent named dihydrolevoglucosenone (Cyrene). Chapter 10, combines all earlier experiments into rigorous process simulations to investigate the potential of Cyrene in the separation of an apolar mixture.