Power-saving airlift bioreactor with helical sieve plates: Developmental and performance studies

Abstract

This study investigated the influence of the geometry of the draft tube on the mass transfer and energy efficiency in the airlift reactor with helical sieve plate (ALR-HSP). The power consumption efficiency was 46%–53% higher than the control condition by optimizing the draft tube. A set of empirical equations was used to describe the gas holdup and volumetric mass transfer coefficients corresponding to the geometry of draft tubes in the ALR-HSP for the water–air system. The comparative cultivation of Pichia pastoris was carried out using the ALR-HSP and the conventional airlift reactor (CALR). The biomass increased by 20%, the maximal specific growth rate during the logarithmic growth phase nearly doubled, and volumetric oxygen transfer coefficient increased by 21%–47% under the same culture conditions. Results preliminarily demonstrated the superior performance and practicability of the ALR-HSP in enhancing oxygen transfer efficiency and aerobic biological reaction efficiency.