摘要
CO2的大量排放是造成温室效应的主要因素,对全球排放的CO2进行捕集非常重要。今采用浸渍法将PEI(聚乙烯亚胺)负载到KIT-6介孔分子筛孔道表面上,使孔的吸附作用和胺的吸收作用相结合,制备出吸附容量大和选择性高的CO2吸附剂,从穿透时间、吸附量、分离因子等方面研究了PEI负载率对CO2吸附性能的影响。结果表明:KIT-6介孔分子筛经PEI改性后对CO2的吸附量和选择性增强。随着PEI负载量的增大,吸附剂对CO2的吸附性能先增大后降低,当PEI负载率为0.6时,CO2的吸附量和分离因子分别达到最大值为2.09 mmol?g?1和30.56,为无负载时的6.0倍和7.2倍。随着温度的升高,PEI改性吸附剂对CO2的吸附量呈增长趋势。再生实验表明吸附饱和的PEI改性吸附剂在378 K条件下能够完全再生,且具有较好的循环再生稳定性。
CO2 capture has gained great attention due to its accumulation in the atmosphere, which is widely agreed as the predominant cause of greenhouse effect. In order to find an efficient adsorbent with high CO2 adsorption capacity and separation selectivity, mesoporous silica KIT-6 was synthesized by hydrothermal method and its amine-functionalized by impregnating it with PEI （polyethylenimine）. The CO2 adsorption performances of KIT-6 and its modified ones were evaluated by using a dynamic adsorption apparatus. The effects of different PEI-loading ratioes on the adsorption of CO2 were investigated by the changes of breakthrough time, adsorption capacity and separation coefficient. The results show that PEI-modified KIT-6 adsorbent could greatly enhance CO2 adsorption amount and the separation coefficient between CO2 and N2. The CO2 adsorption performance increases with PEI-loading and then decreases. When the PEI-loading ratio is 0.6, the adsorption amount of CO2 and the separation selectivity reach their maximum value of 2.09 mmol＆#215;g-1 and 30.56, respectively, which are 6.0 times and 7.2 times higher than that of KIT-6 without PEI loading. Moreover, the CO2 adsorption capacity of PEI-modifies KIT-6 increases with temperature. Besides, the saturated PEI-modified adsorbent can be fully regenerated at 378 K and the regenerated adsorbent shows fairly good stability in 20 cycles of adsorption/regeneration.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2014年第1期171-176,共6页
Journal of Chemical Engineering of Chinese Universities
关键词
KIT-6
聚乙烯亚胺
吸附分离
二氧化碳
KIT-6KIT-6
polyethylenimine
adsorption separation
carbon dioxide
