Comprehensive Analysis of Pressure Drop Phenomena in Rotating Packed Bed Distillation: An In-Depth Investigation

A rotating packed bed (RPB) is an innovative intensification technology that improves its separation capabilities in high-gravity conditions. This process increases efficiency with smaller equipment size and footprint than conventional packed columns. Although significant advancements have been made regarding RPBs, most studies only focused on single or dual rotor configurations in addressing dry pressure drop. Hence, multiple rotor systems in industrial settings can enhance economic efficiency by minimizing the necessity for numerous RPBs. This study investigated the pressure drops and holdup in a three-stage rotor-based RPB under actual process conditions using natural gas as the feed. A novel pressure drop correlation was introduced based on the nitrogen removal process from the natural gas in continuous RPB distillation operations. Consequently, the correlation between centrifugal acceleration, turbulent, and momentum effects demonstrated remarkable accuracy within ±15%. This outcome also highlighted the importance of meticulous design considerations in RPB-based applications due to the complex correlation between centrifugal forces, liquid holdup, and gas flow rates. The reflux feed ratio, liquid holdup, rotating speed, and F-factor effects were examined to comprehend the RPB distillation process. Overall, the correlations between the critical parameters offered crucial insights to prevent process upsets (such as flooding), contributing to advancing RPBs in practical industrial settings.