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测定了饱和烃和不饱和烃分子在一价阳离子交换型ZSM-5沸石分子筛上的吸附等温线。探讨了微孔体积填充理论、Wilkins方程和Langmuir吸附理论对以上吸附体系的适用性;测得的吸附等温线用最小二乘法和解线性方程组借助电子计算机进行拟合得出相应的回归方程。实验结果表明,Langmuir吸附理论能较好地描述环己烷在氢型和碱金属阳离子交换型ZSM-5沸石上的吸附体系,计算出的极限吸附量a_o值与实验值相符,但对其他体系未得满意结果:二常数的Wilkins方程可用于求算吸附体系的初始吸附热,并能较好地描述等温线的低压部分;与以上各理论比较,微孔体积填充理论能更满意地表征我们所研究的吸附体系,籍以计算了极限吸附量a_o,分布级数n和特征吸附功E值三个物理常数,并为一价阳离子交换型ZSM-5沸石上对苯和环己烷等分子的吸附作用主要是色散力作用提供有力依据。
The adsorption isotherms of saturated and unsaturated hydrocarbons on monovalent cation-exchanged ZSM-5 zeolites were determined. The applicability of micropore volumetric packing theory, Wilkins equation and Langmuir adsorption theory were discussed. The adsorption isotherms were fitted by the computer with least square method and the linear equations were fitted to get the corresponding regression equations. The experimental results show that the Langmuir adsorption theory can well describe the adsorption system of cyclohexane on ZSM-5 zeolite with hydrogen-type and alkali-metal cation exchange. The calculated limit adsorption value a_o is consistent with the experimental value. However, for other systems Unsatisfactory results: The two-constant Wilkins equation can be used to calculate the initial adsorption heat of the adsorption system and to better characterize the low pressure part of the isotherm. In contrast to the above theories, the micropore volumetric packing theory can characterize us more satisfactorily The adsorption system studied was designed to calculate the three physical constants of the limit adsorption amount a_o, the distribution order number n and the characteristic adsorption work E value, and the molecular weight of benzene and cyclohexane on the monovalent cation-exchanged ZSM-5 zeolite The adsorption effect is mainly to provide a strong basis for the role of dispersion force.