The liquid-liquid homogeneity of a four-phase simulated hydrocarbon-based bioprocess in a bubble column reactor

摘要

BACKGROUND Bubble column reactors (BCRs) can be used for upgrading hydrocarbons to high-value products via biological oxidation mediated by hydrocarbon-metabolizing organisms. However, spatial phase dispersion homogeneity becomes a critical parameter which is needed for scale-up calculations, especially in BCRs, where fluid mixing is only enacted through sparging. RESULTS In this study, the homogeneity of a multiphase hydrocarbon-based bioprocess system was measured in a large bench-scale BCR, with inner diameter of 15 cm and height of 90 cm. Multiphase dispersion measurement was done under a range of operational conditions such as hydrocarbon concentrations (H-C), solids (deactivated yeast) loading (S-L) and superficial gas velocities (U-G). It was found that in a three-phase system (air-water-hydrocarbon), high U-G (2 cm s(-1)) was required to achieve homogeneity. However, in a four-phase system (air-water-hydrocarbon-yeast), the addition of yeast changed the fluid properties (mainly the surface tension) and therefore enhanced the homogeneity at the minimum U-G (1 cm s(-1)). CONCLUSIONS This article firstly illustrates multiphase homogeneity in multiphase systems, which needs to be examined when dispersion systems are being used, and secondly proposes a method for evaluating this parameter. (c) 2019 Society of Chemical Industry