氢同位素气体的新型动力学吸附模型

New dynamic model of gas adsorption for hydrogen isotopes

将氢同位素气体在多孔吸附剂表面上的吸附脱附过程假设为简单对峙反应,提出了一个适用于体积法计算气体动力学吸附速率常数的数学模型。模型可考察温度与初始压力对动力学吸附速率的影响,且能较好地计算不同压力下氢气与氘气在微孔分子筛4A,5A,Y,10X与介孔分子筛CMK-3,SBA-15上的动力学吸附速率常数。当分子筛孔径为0.5 nm时动力学吸附选择性最大,可高达2.48。介孔分子筛的动力学吸附选择性则较小,表明大孔径的吸附剂不利于氢同位素气体混合物的分离。

The process of hydrogen isotope gas adsorption and desorption on porous adsorbents was assumed by a simple opposing reaction. The mathematical model for the volumetric method was proposed to calculate dynamic rate constants of gas adsorption. The effects of temperature and initial pressure to kinetic adsorption rates were investigated in the model. Moreover,the dynamic adsorption rate constants for hydrogen and deuterium on different adsorbents,including microporous molecular sieves 4A,5A,Y,10 X and the mesoporous molecular sieve CMK-3,SBA-15,were well calculated at different pressures. The largest dynamic adsorption selectivity was up to 2. 48 when the pore size of adsorbents was 0. 5 nm. However,the dynamic adsorption selectivity for mesoporous molecular sieves was small,which showed that the adsorbents with big pore size were not beneficial to separate the gas mixtures of hydrogen isotopes.