Zhou Anning, Ma Xiaoliang, Song Chunshan
Clean Fuels and Catalysis Program, The Energy Institute, and Department of Energy & Geo-Environmental Engineering, The Pennsylvania State University, 209 Academic Projects Building, University Park, Pennsylvania 16802, USA.
J Phys Chem B. 2006 Mar 16;110(10):4699-707. doi: 10.1021/jp0550210.
This work examines the effects of structural and surface properties of carbon materials on the adsorption of benzothiophene (BT), dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) in the presence of 10 wt % of aromatics in liquid alkanes that simulate sulfur compounds in diesel fuels. The equilibrium-adsorption capacity varies significantly, from 1.7 to 7.0 mg-S/g-A. The results show that different carbon materials have significantly different sulfur-adsorption capacities and selectivities that depend not only on textural structure but also on surface functional groups. The adsorption of multi-ring sulfur compounds on carbon materials was found to obey the Langmuir isotherm. On the basis of adsorption tests and the characterization of carbon materials by BET and XPS, the oxygen-containing functional groups on the surface appear to play an important role in increasing sulfur-adsorption capacity. The adsorption-selectivity trend of the carbon materials for various compounds increases in the order of BT < naphthalene < 2-methylnaphthalene < DBT < 4-MDBT < 4,6-DMDBT, regardless of carbon material types. This selectivity trend for sulfur compounds is dramatically different and almost opposite from that previously observed for adsorption over nickel-based adsorbents. The regeneration of spent activated carbons was also conducted by solvent washing. The high-adsorption capacity and selectivity for methyl DBTs indicate that certain activated carbons are promising adsorbents for selective adsorption for removing sulfur (SARS) as a new approach to ultra deep desulfurization of diesel fuels.
本研究考察了在模拟柴油燃料中含硫化合物的液态烷烃中，当芳烃含量为10 wt%时，碳材料的结构和表面性质对苯并噻吩（BT）、二苯并噻吩（DBT）、4-甲基二苯并噻吩（4-MDBT）和4,6-二甲基二苯并噻吩（4,6-DMDBT）吸附的影响。平衡吸附容量变化显著，为1.7至7.0 mg-S/g-A。结果表明，不同的碳材料具有显著不同的硫吸附容量和选择性，这不仅取决于纹理结构，还取决于表面官能团。发现多环硫化合物在碳材料上的吸附符合朗缪尔等温线。基于吸附试验以及通过BET和XPS对碳材料的表征，表面的含氧官能团似乎在提高硫吸附容量方面发挥着重要作用。无论碳材料类型如何，碳材料对各种化合物的吸附选择性趋势按BT < 萘 < 2-甲基萘 < DBT < 4-MDBT < 4,6-DMDBT的顺序增加。这种硫化合物的选择性趋势与先前在镍基吸附剂上观察到的吸附趋势显著不同且几乎相反。还通过溶剂洗涤对废活性炭进行了再生。对甲基DBT的高吸附容量和选择性表明，某些活性炭作为柴油燃料超深度脱硫的一种新方法——选择性吸附脱硫（SARS）的吸附剂具有广阔前景。
