以实验数据为依据,结合双Langmuir模型研究了用高比表面活性碳微球材料分离H2中少量CO2的行为.在实验中,用高精度的IGA-003重力吸附仪测定了温度为298、273和268K,压力在0-1.8MPa范围内CO2、H2及n(CO2)∶n(H2)=1∶9混合物在活性碳微球中的吸附等温线.比较不同吸附模型的计算结果与实验数据,结果表明,双Langmuir模型与实验结果拟合得较好;而且通过结合理想吸附溶液理论,该模型可以准确地计算不同的混合物体系(包括H2-CO2体系)的吸附量和吸附选择性.利用该模型求解了不同温度下各组分的分吸附量,得到了CO2的吸附选择性;在268K和1.7MPa下,CO2的吸附选择性可达到73.4,表明活性碳微球是一种优秀的吸附H2中少量CO2的材料.
On the basis of experimental data, double-Langmuir (DL) model was used to investigate the adsorption and separation of hydrogen and carbon dioxide in activated mesocarbon microbeads with high specific surface. Pure and binary adsorption isotherms of carbon dioxide and hydrogen (mole ratio is 1:9) in activated mesocarbon microbeads were measured using the high-precision intelligent gravimetric analyzer at temperature of 298, 273 and 268 K, and the pressure ranging from 0 to 1.8 MPa. In order to get adsorption amount of the single component of mixture gas, the DL model and the ideal adsorbed solution theory (IAST) were combined. The combined method can be applied to carbon dioxide and hydrogen binary systems perfectly. The calculated results indicated that the selectivity of carbon dioxide can reach 73.4 at 268 K and 1.7 MPa, which suggests that the activated mesocarbon microbead was an excellent candidate for the removal of carbon dioxide in hydrogen/carbon dioxide mixtures.