Co对Cu^+-13X分子筛选择吸附脱硫性能的影响

Effect of Co on Selective Adsorption Desulfurization Performance of Cu^+-13X Molecular Sieves

采用液相离子交换法制备了Cu+-13X和Co2+/Cu+-13X两种分子筛吸附剂,运用XRD,SEM,FTIR等手段对其进行表征。通过静态吸附实验与动力学吸附实验研究了两种吸附剂对模拟汽油的吸附性能,并采用Langmuir模型对静态吸附平衡数据进行拟合,同时采用Crank单孔扩散模型对动力学吸附数据进行拟合。实验结果表明,当Co2+/Cu+-13X吸附剂中Co含量为2.35%(w)时,Co2+/Cu+-13X吸附剂的吸附脱硫效果最佳;Co2+/Cu+-13X吸附剂对噻吩(TP)和苯并噻吩(BT)的最大吸附量相对于Cu+-13X吸附剂分别提高了42.1%和18.8%;Co与Cu之间可发生协同作用,Co2+抑制Cu+向Cu2+的转换,有助于提高吸附剂的脱硫性能;两种吸附剂与噻吩类硫化物之间主要是π配位作用,不存在S-M配位作用;采用Crank单孔扩散模型可很好地描述两种吸附剂的动力学吸附过程,且在TP和BT双组分动力学吸附过程中,Co2+可提高Cu+-13X吸附剂对BT的吸附选择性。

Cu^＋-13X and Co^2＋/Cu^＋-13X molecular sieves as adsorbents were prepared by a liquid phase ion exchange method and characterized by means of XRD,SEM and FTIR.The performances of the adsorbents for the selective adsorption desulfurization of simulative gasoline containing thiophene（TP） and benzothiophene（BT） were studied through static adsorption and kinetics adsorption experiments.The static adsorption equilibrium data were fitted by the Langmuir model and the kinetics adsorption data were fitted by the Crank diffusion model.The experimental results showed that the performance of Co^2＋/Cu^＋-13X with 2.3 5%（w） of Co for the selective adsorption desulfurization was the best.Compared with the Cu^＋-13X molecular sieve,the maximum adsorbing capacity of Co^2＋/Cu^＋-13X molecular sieve for TP and BT increased by 42.1% and 18.8%,respectively.The synergistic reaction between Co and Cu can inhibit the conversion of Cu^＋ to Cu2＋,which improves the desulfurization performance of the Cu^＋-13X adsorbent.There is the π complexation mainly between the two molecular sieves and thiophenic sulfur,not the S-M complexation.The kinetics adsorption data were fitted well by the Crank diffusion model.In the TP and BT two-component kinetics adsorption,the load of Co^2＋ increased the adsorptive selectivity of the Cu^＋-13X molecular sieves to BT.