Scaling up Trickle Bed Reactor for Gas Fermentation Technology: The Effect of Temperature and Reactor Characteristics on Mass Transfer

The increasing demand for efficient and sustainable industrial processes has accelerated research into green alternatives. Gas fermentation in a trickle bed reactor is a promising technology; however, optimal scaling up is still challenging. A mass transfer model is crucial for identifying bottlenecks and suggesting design improvements to optimize the scale-up of TBR for gas fermentation. This study explores the effects of temperature, reactor dimensions, and packing material size on the volumetric mass transfer coefficient (kLa) in a commercial-scale trickle bed reactor (TBR). Using dynamic mass transfer modeling, the research results highlight that thermophilic conditions (60 °C) significantly enhance kLa and mass transfer rates for H2, CO, and CO2, despite reduced gas solubility at higher temperatures. Additionally, packing material of smaller particles improves kLa by increasing the surface for gas–liquid interaction, while reactor dimensions, particularly volume and diameter, are shown to critically influence kLa. This study provides valuable insights into optimizing TBR design and scale-up, emphasizing the importance of thermophilic conditions, proper packing material selection, and reactor geometry for efficient gas–liquid mass transfer in syngas (a mixture of H2, CO, and CO2) biological conversion. Overall, the findings offer practical guidelines for enhancing the performance of industrial-scale TBR systems.