基于活性炭吸脱附测试的杜比宁吸附方程修正表达式

Modified Expression of Dubinin-Radushkevich Equation Based on Adsorption and Desorption Tests of Activated Carbon

现有研究证明杜比宁吸附方程(D-R方程)在高相对压力区(2.59<[ln(p0/P)]^2<10),存在较为明显的欠拟合问题(P为气体的平衡压力,p0为实验温度下的饱和蒸汽压).基于此提出了活性炭材料在2.59<[ln(p0/P)]^2<10范围内的D-R方程的修正表达式,并通过活性炭吸脱附测试获取了3种活性炭在不同相对压力下的氮气吸附量,对实验数据进行分段拟合.拟合结果表明,在2.59<[ln(p0/P)]^2<10范围,所提出的修正表达式拟合精度高于直接使用D-R方程.

Previous studies showed that Dubinin-Radushkevich equation(D-R equation)does not describe the microporous adsorption well in the partial region of 2.59<[ln(p0/P)]^2<10(P is the balance pressure of adsorbate,p0 is the saturated vapor pressure at the experiment temperature).A modified expression of D-R equation is proposed herein for activated carbon materials in the range of 2.59<[ln(p0/P)]^2<10.The adsorption capacity of the three activated carbon adsorbents at different relative pressures was tested with adsorption and desorption experiments,and the experimental data were fitted using proposed equations and original D-R equation.Results showed that in the range of 2.59<[ln(p0/P)]^2<10,the proposed equations can describe microporous adsorption more accurately than the original D-R formula.