水对胺改性吸附剂吸附分离CO_2的影响

Effect of water content on amine-modified adsorbent for separation of CO_2

针对燃煤电厂烟道气中CO2的捕集,采用变压吸附法,从穿透时间、吸附量、分离因子、氨基利用率等方面研究了TEA(三乙醇胺)负载率对胺改性硅胶吸附分离CO2的影响,并进一步考察了胺改性吸附剂中含水量对CO2分离性能的影响。结果表明:TEA改性硅胶对CO2的选择性增强,TEA负载率越高,分离因子越大,TEA负载率为0.8时的分离因子为3.86,是无负载时1.7倍;水的存在能大幅度增强CO2的吸附,水负载率越高,分离因子越大,水负载率为0.35时的分离因子高达24.50,为无水时的7倍,且常温下吸附剂仍可完全再生并具有良好稳定性;氨基利用率随TEA负载率的增大而降低,随水负载率的增大而增大。

Regarding to CO2 capture from the flue gas of coal-fired power plants, by effects of triethanolamine （TEA） loading ratio on the separation of COs were breakthrough pressure studied swing adsorption, the from the aspects of time, adsorption capacity, separation factor, amino-group utilization etc.. The influence of water content on the separation performance of the amine-modified adsorbent was further investigated. The results show that for TEA-modified adsorbent the separation selectivity of CO2 increases. The higher the TEA loading ratio is, the bigger the separation factor is. When the TEA loading ratio is 0.8, the separation factor reaches 3.86, which is 1.7 times that of unloaded sorbent. The presence of water can greatly enhance the adsorption for COs. The higher the water loading ratio is, the bigger the separation factor is. When the water loading ratio is 0.35, the separation factor reaches as high as 24.50,which is 7 times that of anhydrous sorbent. The adsorbent can fully regenerate and show fairly good stability at ambient temperature whether there is water or not. The amino-group utilization decreases with the increase of TEA loading ratio, and increases with the increase of the water loading ratio.