动力波洗涤器中碱液吸收低浓CO_2的传质特性

Mass transfer properties of dilute CO_2 absorption into NaOH solution in dynawave scrubber

为研究动力波洗涤器内的气液传质特性,在动力波洗涤器中,进行NaOH溶液吸收混合气体中微量CO2气体的吸收实验。参考填料塔中钠碱溶液吸收低浓气体的传质模型,测定了动力波洗涤器中NaOH溶液吸收低浓CO2的气相体积总传质系数KGa及吸收效率η。研究了气相速度、NaOH溶液质量分数及液气比对KGa的影响,结果表明:KGa随着气相速度及NaOH溶液质量分数的增加而增大,但NaOH溶液质量分数小于气相速度对KGa的影响;随着液气比的提高,KGa逐渐减小,η开始随着液气比的提高而增加,但到一定数值后,效果不明显;回归了KGa的准数关联式,并依据液气比对KGa及η的综合评价,提出洗涤管直径为100 mm,NaOH溶液质量分数为10%,液气比操作范围在0.005—0.025时,动力波洗涤器具有较高的综合传质性能,为工业应用提供参考。

The experiment of dilute CO2 absorption into NaOH solution was carried out to study the gas-liquid mass transfer characteristics in a dynawave scrubber.Based on the mass transfer model of dilute CO2 absorption into NaOH solution in a packed tower,the volumetric mass transfer coefficient KGa of dilute CO2 absorption into NaOH solution and the absorption efficiency η in dynawave scrubber were investigated.The effects of gas flow velocity,the mass fraction of NaOH solution,and liquid-gas ratio on KGa were investigated.The result shows that KGa increases with the increase of gas flow velocity and the mass fraction of NaOH solution,but the effect of the mass fraction of NaOH solution on KGa is less than that of gas flow velocity.With the increasing of liquid-gas ratio,the KGa decreases gradually,and the CO2 absorption efficiency η increases at the beginning,but to a certain value,the effect is not obvious.The correlations for the KGa were worked out.Based on the comprehensive effect of liquid-gas ratio on KGa and η,it is proposed that when the diameter of scrubbing pipe is 100 mm,the mass fraction of NaOH is 10% and the operating range of liquid-gas ratio is about 0.005-0.025,the dynawave scrubber has a high mass transfer performance.It can be used as a reference for industry application.