基于沸石ZSM-5的CH4/N2/CO2二元体系吸附平衡

采用Rubotherm磁悬浮天平测量CH₄、N₂和CO₂在沸石ZSM-5上的单组分吸附平衡等温线，温度273～353 K，压力0～500 kPa。采用Sips模型、Toth模型和MSL模型对单组分吸附平衡实验数据进行拟合，拟合结果良好，非线性回归得到相应的模型参数。测量双组分CO₂/N₂、CO₂/CH₄和CH₄/N₂在沸石ZSM-5上的竞争吸附平衡等温线，实验温度为293 K，实验压力为0～500 kPa。采用基于Sips模型的理想吸附溶液理论和双组分MSL模型预测双组分气体在沸石ZSM-5上的竞争吸附平衡等温线，并与实验结果进行比较，预测结果良好。比较CO₂/N₂、CO₂/CH₄以及CH₄/N₂体系在沸石ZSM-5上的竞争吸附选择性系数，探究沸石ZSM-5吸附分离烟道气（CO₂/N₂体系）、垃圾填埋气（CO₂/CH₄体系）或煤层气（CH₄/N₂体系）的可行性，为将来进行工艺设计提供基础数据。

Binary adsorption equilibrium of CH4, N2 and CO2 on zeolite ZSM-5

Adsorption equilibrium isotherms of CH₄, N₂ and CO₂ on zeolite ZSM-5 were measured by Rubotherm magnetic suspension balance in the pressure range of 0-500 kPa and the temperature range of 273-353 K. Sips model, Toth model and MSL model were used to fit the experimental data with acceptable accuracy, and the model parameters were obtained by the non-linear regression method. Binary adsorption isotherms of CO₂/N₂, CO₂/CH₄ and CH₄/N₂ were measured by the magnetic suspension balance with different compositions in the pressure range of 0-500 kPa at 293 K. The Sips model-based ideal adsorbed solution theory and two-component MSL model were used to simulate the competitive adsorption equilibrium isotherms of CO₂/N₂, CO₂/CH₄ and CH₄/N₂. Furthermore, the selectivity of CO₂/N₂, CO₂/CH₄ and CH₄/N₂ gas mixtures were calculated, and the feasibility of adsorption separation, using zeolite ZSM-5 as adsorbent to separate CO₂ from flue gases (CO₂/N₂), CH₄ from landfill gases (CO₂/CH₄) and coal mine gases (CH₄/N₂) was evaluated.