It is well known that a small amount of surfactant may significantly affect the flow stability in bubble columns, which cannot be interpreted by the slight variation of the liquid physical properties, e.g., surface tension, viscosity or density. The underlying mechanism is relevant to the interfacial dynamics due to surfactant concentration gradient. However, direct resolution of the micro-scale dynamics is challenging, as this requires complicated coupling of direct numerical simulation of interfacial dynamics and surfactant migration. In this study, a simplified correlative model was developed to take into account the surfactant effect on the average drag coefficient in the two-fluid model of CFD simulation. This novel drag model can improve the prediction of gas holdup in the homogeneous regime. By considering both the surfactant effect and swarm effect, the model can also reasonably estimate the gas holdup in the heterogeneous regime. A notable feature of this model is the reproduction of the peak of gas holdup at certain surfactant concentration in the experiments. Furthermore, although the model is based on the experimental data of ethanol solution, it can also predict the gas holdup in the bubble columns of other types of surfactants, e.g., butanol solution.

众所周知，少量的表面活性剂可能会显着影响泡罩塔中的流动稳定性，这不能通过液体物理性质（例如表面张力、粘度或密度）的轻微变化来解释。潜在的机制与由于表面活性剂浓度梯度引起的界面动力学有关。然而，微尺度动力学的直接解析具有挑战性，因为这需要界面动力学和表面活性剂迁移的直接数值模拟的复杂耦合。在这项研究中，开发了一个简化的相关模型，以考虑表面活性剂对 CFD 模拟双流体模型中平均阻力系数的影响。这种新颖的阻力模型可以改进均质状态下含气量的预测。通过同时考虑表面活性剂效应和群体效应，该模型还可以合理地估计非均质状态下的含气量。该模型的一个显着特征是在实验中再现了特定表面活性剂浓度下的气体滞留量峰值。此外，虽然该模型基于乙醇溶液的实验数据，但它也可以预测其他类型的表面活性剂（例如丁醇溶液）在气泡柱中的气体滞留量。