程序升温脱附测定难挥发性有机物吸附相平衡

Estimation of adsorption isotherm of low volatile organic compounds by temperature-programmed desorption

提出一种采用少量程序升温脱附实验就能计算挥发性有机物在不同温度下吸附等温线的方法。该方法以拟平衡吸附动力学为基础,建立难挥发性有机物从吸附剂表面程序升温脱附的模型,采用数值方法对该模型进行求解。采用该模型对程序升温脱附实验测定的图谱进行模拟,获得难挥发性有机物在吸附剂上的吸附相平衡参数,从而确定吸附等温线。运用所提出的方法,对二苯并呋喃在Norit RB1和Chemviron BPL活性炭上的吸附等温线方程进行了估算。估算结果与静态吸附实验测定结果比较吻合,误差不超过10%。

A method enabling the calculation of a series of adsorption isotherms of volatile organic substances at different temperatures was introduced based on a few temperature-programmed desorption（TPD） experiments.In the method,a transient kinetic model was established based on quasi-equilibrium adsorption/desorption between the gas phase and the adsorbent for the rapid readsorption during TPD.The model was numerically solved to fit to experimental TPD data by adjusting the equilibrium parameters.Hence the adsorption isotherm was calculated.This method was applied to study the adsorption isotherms of debenzofuran adsorption on Norit RB1 and Chemviron BPL activated carbons.The estimated results are in good agreement with literature isotherms from static adsorption experiment,the error is less than 10%.