NH_3和CO_2的选择性分离I.间歇吸收机理及影响因素

Selective Separation of NH_3-CO_2 I. Mechanism and Influence Factor of Intermittent Absorption

通过对摩尔比接近于 2∶ 1的 NH3/CO2 混合气体进行选择性吸收研究 ,得到了良好的选择性分离效果 ,选择性分离因子 S1在 2 .0 6～ 7.2 3之间 ,S2 在 2 .86～ 1 0 .63之间 ;考察了气体速率和溶液中 NH3浓度对选择性吸收的影响 ,得到了高气速 ,短接触的结论 ;论证了选择性吸收的机理模型 :NH3的吸收属于气膜控制 ,CO2 的吸收可看作假一级快反应。

Selective absorption has been studied to separate the mixture gas of NH 3/CO 2=2 (mol ratio), the satisfactory selectivity was obtained. The selectivity factor of S 1 is between 2.06～7.23, the ratio of S 2 is between 2.86～10.83. The influence of concentration of NH 3 and gas velocity on selectivity have also been studied. It can be concluded that the high gas velocity and short contact is benefit to selective absorption of NH 3. At last, a mechanism model of selective absorption was demonstrated: the absorption of ammonia is controlled by gas film and the absorption of carbon dioxide is looked as a fast pseudo first order reaction.