高通量炭膜的制备与表征

Preparation and Characterization of High Performance Carbon Membrane

以酚醛树脂为原料,采用热浸渍法在管状氧化铝载体上制备了气体分离用炭膜,考察热浸渍温度对炭膜表面形貌和气体分离性能的影响。结果表明:随着热浸渍涂膜温度的提高,炭膜的厚度逐渐降低,H_2、N_2、CO_2、CH_4的渗透速率先增大后降低,CO_2/CH_4的分离因数变化较小;扫描电镜观察表明,炭膜由多孔结构的支撑体和其上覆盖的分离层组成。利用质量分数为36%的树脂涂膜液,在150℃下涂覆制备的炭膜表面均匀、致密,无明显缺陷,膜层厚度约1.5μm,等摩尔CO_2/CH_4混合气的渗透测试表明,室温下炭膜的CO_2渗透速率达到1.8×10^(-7)mol·Pa^(-1)·m^(-2)·s^(-1),α_(CO_2/CH_4)达到66,远高于其努森扩散值。

Carbon membranes were prepared by hot coating method on α-Al203 tubes with a solution of commercial phenolic resin in the ethanol,and the effect of dip-coating temperature on the properties of carbon membrane was also investigated.The results indicated that the permeability of H2,N2,CO2,CH4 to carbon membrane increased first and then decreased and the CO2/CH4 selectivity of carbon membrane changed a little with the increase of dip-coating temperature using mass fraction 36％ coating solution.SEM observation of carbon membrane indicated that there was a relative dense layer on the porous substrate.When the dip coating operation was carried out at 150℃,the carbon membrane was uniform and dense with 1.5μm thickness.The CO2/CH4 （50/50）mixture permeation test showed that this carbon membrane had very high CO2 permeance of 1.8 ×10-7 mol· Pa-1· m-2 ·s-1 and CO2/CH4 selectivity of 66,higher than the Kundsen value.