磷化氢在改性13X分子筛上的吸附行为

为回收工业废气中的磷化氢(PH3)并资源化,采用浸渍法制备了一种CaCl2改性13X分子筛吸附剂,通过容积法研究了25—70℃PH3气体在改性13X分子筛上的等温吸附行为。结果表明,在实验条件范围内25,40,55,70℃下PH3的饱和吸附量(质量分数)分别为2.528,1.901,1.591,0.925mg/g。Freundlich吸附等温方程很好地模拟了改性13X分子筛对PH3的等温吸附,Langmuir和Henry吸附等温方程对吸附平衡数据的拟合效果不佳表明了改性13X分子筛表面吸附位的不均匀分布。当初始吸附量为0.10mg/g时,等量吸附热值最大,为17.81353kJ/mol,即等量吸附热不超过18kJ/mol,过程为物理吸附,便于PH3气体的解吸。

Adsorption characteristics of phosphine on modified 13X molecular sieve

To recover and utilize phosphine (PH_3) from industrial offgas, the adsorbent of CaCl_2 immersed 13X molecular sieve was prepared. The isotherm adsorption characteristics of phosphine gas on the modified 13X molecular sieve were investigated at 25-70 ℃ by using volumetric method. The results show that the adsorptive mass fraction of phosphine onto the modified 13X molecular sieve at different temperatures were as follows: 2.528, 1.901, 1.591, 0.925 mg/g at 25, 40, 55, 70 ℃ respectively. Freundlich adsorption isotherm equation is more suitable for the description of adsorption process, and the fitting results of Langmuir and Henry equations indicate the heterogeneous characteristics of modified adsorbent. The maximum isosteric heat of adsorption is 17.813 53 kJ/mol at the beginning of adsorption process, which is less than 18 kJ/mol and means that this process is a physical adsorption and convenient for phosphine gas desorption.