采用高速摄像仪对微通道内离子液体/乙醇混合溶液吸收CO_2的传质行为进行了实验研究。考察了弹状流型下气液两相流量比和离子液体浓度对液侧体积传质系数kLa和液侧传质系数kL的影响。当离子液体浓度不变时,kLa、kL均随气液流量比的升高而增大并逐渐趋于恒定。当液相流量不变时,对于不同浓度的离子液体溶液,液侧体积传质系数kLa和液侧传质系数kL随气液流量比的变化曲线出现了交叉点。在交叉点之前,kLa和kL均随着离子液体浓度的增大而减小;在交叉点之后,kLa和kL均随着离子液体浓度的增大而增大。提出了用于预测液侧体积传质系数kLa的新的量纲1经验关联式,预测效果良好。
The mass transfer behavior of CO_2 absorption into ionic liquid/ethanol mixture in microchannel was investigated experimentally using a high speed camera. The influences of the ratio of gas to liquid phase flow rates, the concentration of ionic liquid on the liquid side volumetric mass transfer coefficient(kLa) and liquid side mass transfer coefficient(kL) for slug flow were studied. For a given concentration of ionic liquid, both kLa and kLincrease gradually with increasing the ratio of gas to liquid phase flow rates and then level off. For different concentrations of ionic liquid at a given liquid phase flow rate, there is a transition point in the curve of kLa(kL) as a function of the flow rate ratio of gas to liquid phase. Before this point, kLa(kL) decreases with increasing the concentration of ionic liquid, while reverse tendency is found after the point. A new dimensionless empirical correlation for predicting kLa was proposed, and the predicted values coincide well with the experimental data.