A general enhancement factor model for absorption and desorption systems: A CO₂ capture case-study

This study derives a general method (GM) for reactive absorption and desorption calculation. It connects the Onda's approximation for reversible reactions with the van Krevelen's approach for instantaneous irreversible reactions. It is set-up for a reversible (m+n)-th order, forward reaction kinetics and applied for the CO₂-MEA-H2O second order reversible system. The results show that the GM predicts the two-film theory within 2% accuracy and the surface renewal model within 10% accuracy, both at absorber and desorber conditions and for high driving force and pinch conditions. GM is compared to the ideas of van Krevelen, and Astarita and Savage. An analysis demonstrates how the GM model eliminates many of the limitations of previous approaches. It has a noticeable potential to enhance the accuracy of process simulators without sacrificing the simulation time. It could eliminate the need for conservative and uncertain design and therefore it will lead to more realistic cost estimations.