大温度区间氢的高压吸附等温线模型

Model Fitting for High Pressure Adsorption Isotherms of Hydrogen in Wide Range of Temperature

氢在活性炭上的吸附等温线模型是储氢和分离（或纯化）氢气等工程项目的热力学和工程计算基础。Ｌａｎｇｍｕｉｒ、Ｆｒｅｕｎｄｌｉｃｈ、Ｖｉｒｉａｌ和ＤｕｂｉｎｉｎＡｓｔａｋｈｏｖ方程是用来描述气／固体系吸附等温线最常见的模型。但是它们在大温度范围的适用性从来没有检验过。本文采用７７２９８Ｋ、０７ＭＰａ范围内氢在活性炭上的吸／脱附数据，分别检验了上述四方程式对于实验数据的拟合程度，并以各实验温度下的标准偏差和整个实验范围内的总偏差对各方程的适用性做了定量的比较。结果表明，Ｄ－Ａ方程在全部实验条件下的总平均偏差为３．０％，是实验等温线最贴切的模型；Ｆｒｅｕｎｄｌｉｃｈ方程次之，总偏差为３．３％；Ｌａｎｇｍｕｉｒ方程在１１３Ｋ以上温度下尚能作为等温线模型，但在更低的温度下绝不适用；Ｖｉｒｉａｌ方程与其类似，适用范围是１５３－２９８Ｋ。

The Langmuir equation and one of its modified version, Virial equation and the Dubinin Astakhov equation were fitted to high pressure adsorption isotherms of hydrogen. The isotherms covered the experimental range of 77￣298K and 0￣7 MPa. Standard deviation of a model from the measured values was used as the criteria to compare the fitness of different models. the D A equation and the modified Langmuir equation fit the experimental isotherms very well in the whole range tested. However, the Langmuir equation and the Virial equation can only be applied above a lower limit temperature. Even for the best fit D A equation, abnormal parameter behavior was observed.