H_(2)S对铝基固态胺吸附剂吸附CO_(2)性能的干扰机制

Interference Mechanism of H_(2)S on CO_(2)Adsorption of Aluminum-Based Solid Amine Adsorbent

H_(2)S杂质对固态胺吸附剂吸附CO_(2)性能的干扰机制还缺少全面研究。以Al_(2)O_(3)为载体负载聚乙烯亚胺(PEI)制备铝基固态胺吸附剂(PEI@Al_(2)O_(3)),系统探究了H_(2)S对其CO_(2)吸附容量、吸附速率和循环吸附性能的影响规律。结果表明:H_(2)S与CO_(2)共存时,会相互抢占吸附剂上的胺基活性位点,从而发生竞争性吸附,但在模拟沼气条件(40%CO_(2)+59.5%CH_(4)+0.5%H_(2)S)下,H_(2)S的吸附竞争力远小于CO_(2),H_(2)S吸附被抑制,且二者的最佳吸附温度不一致,在CO_(2)最佳吸附温度下,PEI@Al_(2)O_(3)的CO_(2)吸附容量和循环稳定性均不受H_(2)S干扰。

The interference mechanism of H_(2)S impurity on the CO_(2)adsorption performance of solid amine adsorbents is still lack of comprehensive research.An aluminum-based solid amine adsorbent(PEI@Al_(2)O_(3))was prepared with Al_(2)O_(3)as a support to load polyethyleneimine(PEI),and the influence of H_(2)S on the CO_(2)adsorption capacity,adsorption rate and cyclic adsorption performance of the adsorbent was investigated.The results show that the competitive adsorption occurs when H_(2)S and CO_(2)coexist due to H_(2)S and CO_(2)simultaneously grabbed the active sites of amine groups on the adsorbent.However,the adsorption competitiveness of CO_(2)is larger than that of H_(2)S under the simulated biogas condition(i.e.,40%CO_(2)+59.5%CH_(4)+0.5%H_(2)S),thus inhibiting H_(2)S adsorption.Furthermore,the optimal adsorption temperature of CO_(2)and H_(2)S is inconsistent,and the CO_(2)adsorption capacity and cyclic stability of PEI@Al_(2)O_(3)are not disturbed by H_(2)S at the optimal adsorption temperature of CO_(2).