Numerical modeling of a finned, electrically heated adsorbent bed for the thermal regeneration of molecular sieves in methyl acetate dehydration

The dehydration of organic solvents using molecular sieves is a critical industrial process, yet the conventional regeneration of saturated adsorbents via Temperature Swing Adsorption (TSA) or Pressure Swing Adsorption (PSA) remains energy-intensive, costly, and operationally complex. This study introduces a novel electro-thermal regeneration system that directly supplies the thermal energy required for water desorption through an integrated electric heater embedded within the vessel walls, thereby eliminating the need for hot purge gases and auxiliary equipment. Through a systematic three-dimensional Computational Fluid Dynamics (CFD) analysis using COMSOL Multiphysics, we optimize the design parameters — including internal fin configurations (3, 6, and 12 fins), heater arrangements (belt vs. integrated), vessel materials (iron, aluminum, copper), and cylinder geometry — to enhance temperature uniformity and minimize cycle time. The results demonstrate that an optimized design featuring 12 internal aluminum fins achieves a regeneration cycle time of 21.5 h under ideal environmental conditions (-5 °C). However, under realistic high-ambient-temperature conditions, the cooling phase becomes the primary bottleneck, extending the total cycle time to 42 h. To maintain the required system throughput under these adverse conditions, the cylinder length is increased from 150 cm to 445 cm, effectively decoupling the regeneration time from the 15-hour operational cycle. The novelty of this work lies in: (i) the proposal of a direct electro-thermal regeneration method that bypasses traditional TSA/PSA complexities; (ii) the first systematic numerical optimization of finned adsorbent beds for thermal regeneration; and (iii) the critical evaluation of design performance.