Distillation is one of the oldest and most frequently used separation processes, based on the different boiling points of components in miscible liquid mixtures. Due to its simplicity, high efficiency for various mixtures and the possibility of continuous separation, this method is widely applied in numerous industrial sectors, such as the pharmaceutical, petroleum, food and chemical industries. Despite its many advantages, distillation also has certain limitations. It is an energy-intensive process, which conflicts with sustainable development guidelines. The equipment required to ensure adequate productivity is large, meaning the process demands significant operational space. Additionally, distillation systems are stationary and as a result, distillation is a relatively expensive separation process. The distillation process could be improved, if performed in micro-structured systems, which are characterized by large specific surface areas (high surface-to-volume ratio). This enhances heat and mass transfer within the system, enabling faster separation, easier temperature regulation and, most importantly, greater energy efficiency. Due to smaller reaction volumes, the consumption of chemicals and energy is reduced, along with waste production and environmental impact. Additionally, in micro-distillation, productivity can be easily increased by numbering-up the units. Microdistillation units can also be integrated with other (micro)reactors or analysers, creating a so-called "end-to-end processing" system for seamless production or analysis. In model-based design (MBD) of a microdistillation unit it is essential that after problem description, transport mechanisms definition, and other system characteristics definition, a model is created that mathematically describes and predicts the behaviour of the mixture within the device. After solving the model, a process simulation is carried out, allowing for a deeper understanding of the device's operation and an analysis of the impact of different variables on system performance. This enables the optimization of the process unit before its fabrication, which is one of the key advantages of the MBD approach. Within this research, microstructured distillation device, in which the driving force for separation is capillary force, was developed, and corresponding mathematical models were derived to describe the process. This was followed by numerical model solving, verification and optimization of the distillation process to improve separation efficiency, reduce energy consumption, and enable system scale-up.
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