关键词: 碳膜, 非平衡模拟, 渗透, 氮气, 氧气

The effect of temperature on the permeation of oxygen, nitrogen and their binary gas mixture through carbon membranes were investigated using a dual control volume grand canonical molecular dynamics method. The two-dimensional slit was used instead of one-dimensional pore, and a novel iteration was introduced to overcome the difficulty of ignoring the effect of permeation side pressure and composition on gas transports. The results showed that both oxygen and nitrogen followed Knudsen diffusion mechanism when they permeated through carbon membranes as pure component, respectively. In this case, nitrogen had a rather higher permeability than oxygen. However, oxygen had a higher permeability than nitrogen due to competitive adsorption at low temperature when their mixture flowed through membranes. In addition, the pore width impacted the permeability strongly, especially when the pore was very small, and molecular sieving predominated the separation of oxygen/nitrogen. But at the high temperature adsorption hardly affected the separation of oxygen/nitrogen.

Key words: carbon membrane, non-equilibrium simulation, permeation, nitrogen, oxygen