当前位置: X-MOL 学术Micropor. Mesopor. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Adjusting the proportions of extra-framework K+ and Cs+ cations to construct a “molecular gate” on ZK-5 for CO2 removal
Microporous and Mesoporous Materials ( IF 4.8 ) Pub Date : 2018-03-30 , DOI: 10.1016/j.micromeso.2018.03.034
Jiangfeng Yang , Hua Shang , Rajamani Krishna , Yong Wang , Kun Ouyang , Jinping Li

For the capture of CO2 from flue gas and decarbonization of natural gas streams, an ideal adsorbent should have a high selectivity for CO2 over N2 and CH4. In this work, through adjusting the proportions of extra-framework K+ and Cs+ cations and varying the Si/Al ratios of the zeolite ZK-5, the small “molecular gate” adsorbent ZK-5-n-K has been prepared. An increase in the number of K+ cations prevents the ingress of the larger molecules CH4 and N2, while allowing entry of the smaller CO2; the net result is that CO2 capture from CH4 or N2 is achieved with unusually high selectivity, of the order of 1 × 105. Grand canonical Monte Carlo simulations show that the extra-framework K+ and Cs+ cations are positioned at different locations in the ZK-5; K+ locates near the 8-ring window, whereas Cs+ resides in the interior regions. The separation performances of 12 different K+- and Cs+-doped ZK-5 structures (with four different Si/Al ratios of 3.17, 3.36, 3.46, and 3.57) have been investigated. Transient breakthrough simulations have been used to quantify the CO2 capture performances in four sets of separations: 30%/70%, 5%/95%, and 2%/98% CO2/CH4 mixtures at a total pressure of 1 MPa, and a 15%/85% CO2/N2 mixture at a total pressure of 100 kPa. In all cases, the selectivities were sufficiently high to ensure that the separation performance was primarily governed by the CO2 uptake capacity. The overall conclusion to be drawn from this work is that ZK-5 is a suitable adsorbent for the decarbonization of natural gas.



中文翻译:

调整骨架外K +和Cs +阳离子的比例,以在ZK-5上构建“分子门”以去除CO 2

为了从烟道气中捕集CO 2和天然气流脱碳,理想的吸附剂应具有比N 2和CH 4高的CO 2选择性。在这项工作中,通过调节骨架外K +和Cs +阳离子的比例并改变沸石ZK-5的Si / Al比,制备了小的“分子门”吸附剂ZK-5- n -K。增加K +阳离子的数量可以阻止较大分子CH 4和N 2的进入,同时允许较小CO 2的进入; 最终结果是CO 2从CH 4或N 2捕获的捕获具有非常高的选择性,约为1×10 5。大经典的蒙特卡洛模拟表明,额外的框架K +和Cs +阳离子位于ZK-5中的不同位置。K +位于8环窗口附近,而Cs +位于内部区域。研究了12种不同的K +和Cs +掺杂的ZK-5结构(四种不同的Si / Al比为3.17、3.36、3.46和3.57)的分离性能。瞬态突破模拟已用于量化CO 2在四组分离中的捕集性能:总压力为1 MPa的30%/ 70%,5%/ 95%和2%/ 98%的CO 2 / CH 4混合物和15%/ 85%的CO 2 /总压力为100 kPa的N 2混合物。在所有情况下,选择性都足够高,以确保分离性能主要受CO 2吸收能力的支配。从这项工作中得出的总体结论是,ZK-5是天然气脱碳的合适吸附剂。

更新日期:2018-03-30
down
wechat
bug