Abstract Industrially relevant bioprocesses such as paraffin activation present a complex multiphase system consisting of an aqueous growth medium and an immiscible alkane phase that is aerobically metabolized by active micro-organisms. Thus, the oxygen transfer rate from sparged gas is a key design parameter for which empirical correlations have been proposed to inform bioreactor design. However, a fundamental predictive approach is needed to enable the evaluation of novel multiphase bioreactor designs in silico. This study reports on the development of a fundamental predictive model of oxygen transfer based on computational fluid dynamics. Key findings suggest that the alkane phase impacts the hydrodynamics by turbulence modulation rather than a change in fluid properties. The model-predicted oxygen transfer rate is compared to experimental measurements and shown to have an accuracy similar to empirical correlations. However, only the fundamental model captures complex interactions arising due to the alkane phase and can thus be more readily extrapolated to novel multiphase bioreactor designs. The insights gained in this study will guide future investigations into the simulation of hydrodynamics and oxygen transfer in the presence of micro-organisms, thereby providing a fundamental approach to bioreactor scale-up.

中文翻译：

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三相气液液搅拌釜反应器中流体力学和传质的数值研究

摘要 工业相关的生物过程，如石蜡活化，呈现出一个复杂的多相系统，由含水生长介质和不混溶的烷烃相组成，该相由活性微生物有氧代谢。因此，来自喷射气体的氧气转移率是一个关键的设计参数，已经提出了经验相关性来为生物反应器设计提供信息。然而，需要一种基本的预测方法来评估新型多相生物反应器设计。本研究报告了基于计算流体动力学的氧转移基本预测模型的开发。主要发现表明，烷烃相通过湍流调制而不是流体特性的变化来影响流体动力学。将模型预测的氧气转移率与实验测量值进行比较，并显示出与经验相关性相似的准确性。然而，只有基本模型捕获了由于烷烃相引起的复杂相互作用，因此可以更容易地外推到新的多相生物反应器设计。在这项研究中获得的见解将指导未来对微生物存在下流体动力学和氧气转移的模拟的研究，从而为生物反应器的放大提供一种基本方法。