Fast Screening of Energy and Cost Efficient Intensified Distillation Processes

Abstract

While distillation processes still account for the majority of fluid separations, their low thermodynamic efficiency and the resulting high energy requirements raise concerns towards their sustainability in the face of climate change and global warming. Competing technologies, especially various types of membrane processes and hybrid separation processes promise significant improvements in terms of energy efficiency, but are still not applied widely in the chemical industry. So far, the robustness of distillation remains unmatched by these technologies. In order to improve the energy efficiency of distillation processes different means for energy integration have been developed, ranging from the classical direct heat integration, over different forms of thermal coupling, including dividing wall columns, different types of heat pumps, especially mechanical vapour recompression, to multi-effective distillation. In order to evaluate the most energy and cost efficient distillation process all feasible options, or at least a representative number of configurations, should be considered. The most efficient intensified distillation processes is not only the best option based on robust distillation technology, but also the meaningful competitor for all competing technologies. The current contribution presents a screening tool based on accurate shortcut models that account for non-ideal thermodynamics. The screening tool allows for an automatic and computationally efficient evaluation of a large number of alternative intensified distillation processes for the separation of a given mixture into three product streams. It furthermore allows for a scenario-based evaluation of uncertainty information. The applicability is illustrated for several case studies.