A plug flow model without axial dispersion was utilized to evaluate the mass transfer coefficient in Scenedesmus microalgae culture grown in a split airlift photobioreactor. The local volumetric mass transfer coefficient and the local interfacial area also were calculated at various gas velocity (1.0, 2.0 and 2.8 cm s^–1). In the riser and the downcomer section, the local volumetric mass transfer coefficients were dominated by interfacial area and gas holdup values, and were favored by lower optical densities (ODs) and higher values of superficial gas velocities of microalgae cultures. The OD effects on the liquid side and the local volumetric mass transfer coefficient were analyzed over the growth period divided into three zones: Zone I, for OD ≤0.08; Zone II, OD between 0.08 and 0.19; and Zone III, OD between 0.19 and 0.30. Although the local volumetric mass transfer coefficient was constant axially in the riser, it decreased axially on moving through the downcomer. The estimated local volumetric mass transfer coefficient was found always to be higher than that estimated from the available correlations. © 2020 Society of Chemical Industry (SCI)

中文翻译：

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圆柱形气举光生物反应器中浮藻微藻培养的局部体积传质系数估计。

利用没有轴向分散的活塞流模型来评估在分离式气举光生物反应器中生长的Scendesmus微藻培养物中的传质系数。还计算了在各种气体速度（1.0、2.0和2.8 cm s ^–1时）的局部体积传质系数和局部界面面积）。在立管和降液管部分，局部体积传质系数受界面面积和气体滞留率值支配，而微藻类培养物的较低光密度（OD）和较高的表观气体流速值则有利于局部体积传质系数。在整个生长期内，分析了OD对液侧的影响和局部体积传质系数，将其分为三个区域：I区，OD≤0.08；II区，OD在0.08至0.19之间；III区，OD在0.19至0.30之间。尽管在提升管中局部体积传质系数在轴向上是恒定的，但在通过下降管时轴向上减小了。发现估计的局部体积传质系数总是高于根据可用的相关性估计的系数。©2020年化学工业协会（SCI）