Windowed Carbon Nanotubes for Efficient CO2 Removal from Natural Gas
Windowed Carbon Nanotubes for Efficient CO2 Removal from Natural Gas
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DOI：
10.1021/jz301576s
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发表时间：
2012-11-15
影响因子：
5.7
通讯作者：
Jiang, De-en
中科院分区：
文献类型：
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作者：
Liu, Hongjun;Cooper, Valentino R.;Jiang, De-en
我们从分子动力学模拟表明，开窗碳纳米管可以有效地分离CO2从CO2/CH 4混合物，类似于用于气体分离的聚合物中空纤维。四个CO2/CH 4混合物与10，30，50，和80%的CO2作为施加的压力从80到180巴的函数进行了研究。在所有模拟条件下，仅观察到CO2渗透; CH 4在可访问的时间尺度内被纳米管壁上的氮官能化窗口或孔完全拒绝，同时保持沿着管的快速扩散速率。与典型的聚合物膜的100 GPU相比，估计的时间依赖性CO2渗透范围为10（7）至10（5）GPU（气体渗透单位）。根据渗透自由能势垒的差异，估计CO2/CH 4选择性类似于10（8）。这项工作表明，有窗口的碳纳米管可以用作一种高效的介质，可配置在中空纤维状模块中，用于从天然气中去除CO2。
We show from molecular dynamics simulations that windowed carbon nanotubes can efficiently separate CO2 from the CO2/CH4 mixture, resembling polymeric hollow fibers for gas separation. Four CO2/CH4 mixtures with 10, 30, 50, and 80% CO2 are investigated as a function of applied pressure from 80 to 180 bar. In all simulated conditions, only CO2 permeation is observed; CH4 is completely rejected by the nitrogen-functionalized windows or pores on the nanotube wall in the accessible time scale, while maintaining a fast diffusion rate along the tube. The estimated time-dependent CO2 permeance ranges from 10(7) to 10(5) GPU (gas permeation unit), compared with similar to 100 GPU for typical polymeric membranes. CO2/CH4 selectivity is estimated to be similar to 10(8) from the difference in free-energy barriers of permeation. This work suggests that a windowed carbon nanotube can be used as a highly efficient medium, configurable in hollow-fiber-like modules, for removing CO2 from natural gas.