球状纳米介孔碳和HZSM-5分子筛在二苯并噻吩吸附脱硫中的应用

Application of mesoporous carbon nanosphere and HZSM-5 zeolite in dibenzothiophene adsorption desulfurization

采用软模板法制备了粒径范围为50 nm~100 nm的球状纳米介孔碳(MCN),与HZSM-5分子筛机械混合获得介/微孔混合吸附剂,用于二苯并噻吩的吸附脱硫研究。XRD、BET、SEM和TEM等分析结果表明,MCN比表面积为214 m^(2)/g,孔径为5.1 nm,混合吸附剂的比表面积、孔容、孔径均处于MCN和HZSM-5分子筛两者之间,且两者混合均匀。吸附脱硫实验表明,HZSM-5分子筛对二苯并噻吩的吸附脱硫率最差(脱硫率4.8%),而MCN的脱硫性能最优(脱硫率70%),混合吸附剂中随MCN含量增加二苯并噻吩的吸附脱硫性能逐渐提高,且MCN表现出了较好的可重复性能,经过4次循环后吸附容量保留率为79%。Freundlich等温模型比Langmuir等温模型更适合描述二苯并噻吩在上述吸附剂表面的吸附过程,吸附动力学实验数据说明二苯并噻吩在该系列吸附剂上的吸附更符合二级动力学模型。

Mesoporous carbon nanosphere(MCN)with uniform particle size from 50 nm to 100 nm was prepared by soft template method.MCN and HZSM-5 zeolite were mechanically mixed according to different mass ratios to obtain a series of mesoporous/mi-croporous mixtures.These mixtures were characterized with multiple approaches including XRD、BET、SEM andTEM.Thecharac-terization results showed that the specific surface area of MCN was 214 m^(2)/g,and its pore diameter was 5.1 nm.The specific sur-face area,pore volume and pore diameter of mesoporous/microporous mixtures are between that of MCN and HZSM-5 zeolte,which were mixed evenly.The series of mixtures were used as adsorbents to study the adsorption desulfurization performance of dibenzo-thiophene on these adsorbents.The desulfurization rate of HZSM-5 zeolte for dibenzothiophene is the worst(4.8%),and that of MCN is the highest(70%).With the increase of the content of MCN,the desulfurization performance of mesoporous/microporous mixtures for dibenzothiophene gradually improves.MCN showed good repeatability,and the retention rate of adsorption capacity was 79%after four cycles.Freundlich isothermal model is more suitable than Langmuir isothermal model to describe the adsorption process of dibenzothiophene on the above adsorbents surface and the kinetics experimental datas show that the adsorption of dibenzothiophene on this series of adsorbents is more in line with the second-order kinetic model.