Adsorption of Dibenzothiophenes on Nanoporous Carbons: Identification of Specific Adsorption Sites Governing Capacity and Selectivity

Introduction Removal of dibenzothiophene (DBT) and 4,6dimethyldibenzothiophene (DMDBT), which are considered as refractory species, to low level of 30 ppm from diesel fuel is not a trivial task. Activated carbons have been shown as good adsorbents of dibenzothiophenic compounds [1-3]. Introduction of oxygen functional groups on the surface results in a specific adsorption of dibenzothiophenic species via oxygen-sulfur interactions [1]. On the other hand, in our recent reports we have shown that both, surface porosity and acidity/polarity are important for desulfurization from model diesel fuel of low sulfur content [3]. Although, mainly the volume of pores similar in size to DBT and DMDBT molecules governs the capacity, the performance can be significantly enhanced when the oxygen groups are present in larger pores. The objective of this study is to evaluate the performance of the polymer derived carbons with specific surface chemistry in desulfurization process.