摘要
通过 nanoporous 碳膜的纯 H2,公司, N2, O2 和 CH4 气体的散开被执行非平衡调查分子的动力学(NEMD ) 模拟。为与各种各样的毛孔宽度通过碳膜扩散的纯气体的流动,运输扩散性和激活精力被调查。模拟结果表明那运输扩散性与温度和毛孔宽度增加,并且它的价值有 10 的大小 ? 7 m2 路 s ? 1 为在 273 ~ 300 K 的大约 0.80 ~ 1.21 nm 的毛孔宽度。为通过有各种各样的毛孔宽度的膜的气体散开的激活精力是大约 1 鈥吗?kJ 路 m ol ? 1。运输扩散性的结果与 Rao 和政府的是可比较的(J。Membr。Sci, 1996 ) ,显示 NEMD 模拟方法是为在多孔的材料为气体预言运输扩散性的一个好工具,它精确地总是是困难的是由实验测量了。
Diffusion of pure H2, CO, N2,O2 and CH4 gases through nanoporous carbon membrane is investigated by carrying out non-equilibrium molecular dynamics (NEMD) simulations. The flux, transport diffusivity and activation energy for the pure gases diffusing through carbon membranes with various pore widths were investigated. The simulation results reveal that transport diffusivity increases with temperature and pore width, and its values have a magnitude of 10^-7 m^2·s^-1 for pore widths of about 0.80 to 1.21 nm at 273 to 300 K. The activation energies for the gases diffusion through the membrane with various pore widths are about 1-5 kJ·mol^-1, The results of transport diffusivities are comparable with that of Rao and Sircar (J. Membr. Sci., 1996), indicating the NEMD simulation method is a good tool for predicting the transport diffusivities for gases in porous materials, which is always difficult to be accurately measured by experiments.
基金
Supported by the state Key Development Program for Basic Research of China (2003CB615707) and the National Natural Science Foundation of China (20736005).
关键词
H2
CO
N2
O2
CH4
碳膜
扩散
化工过程
non-equilibrium molecular dynamics, carbon membrane, transport diffusivity, flux, activation energy