Optimal stratification improves efficiency in fixed-bed separation

Several studies show that stratified fixed-bed separation columns have the potential to improve the process performance in various applications compared to homogeneous columns. However, the actual target for designing the stratification remained unclear. In a previous contribution, we developed a model-based design strategy based on an optimal control approach. To study the implication of that approach, we here performed experiments with optimally designed stratified activated carbon adsorption columns to remove phenol from water. Two different case studies were investigated. In the first case study, the optimal stratified column improved the breakthrough curve by 48.26% compared to a homogeneous column using the mean particle diameter as a constraint. In the second case study, the optimal stratified column achieved a 51.87% sharper breakthrough curve compared to a non-optimized stratified column using the pressure drop as a constraint. The presented technique is not limited to adsorption columns but holds implications for further unit operations, such as liquid chromatography.