چكيده لاتين
The presence of organosulfur compounds in hydrocarbon fuels represents one of the major environmental and industrial challenges, as combustion of these compounds leads to the emission of pollutant gases such as SOx, resulting not only in air pollution but also in acid rain and corrosion of industrial equipment. Therefore, the development of efficient methods for fuel desulfurization has become an essential requirement in the refining industry.
The conventional hydrodesulfurization (HDS) process, although highly effective in removing many sulfur-containing compounds, faces serious limitations in the removal of stable aromatic compounds such as dibenzothiophene (DBT). The aromatic structure of these compounds provides significant resistance to hydrogenation, making their removal difficult. Consequently, the use of complementary methods to eliminate such compounds is inevitable. Among these, electrochemical desulfurization has recently attracted attention as an innovative and effective approach due to its environmental compatibility, mild operating conditions, lack of need for high temperature and pressure, and controllable process parameters.
In this study, a reticulated vitreous carbon (RVC) electrode was employed to remove the sulfur-containing compound DBT from a model fuel. The RVC electrode was chosen for its three-dimensional porous structure, high active surface area, and low pressure drop (particularly advantageous in continuous flow systems). However, initial results indicated that the process efficiency for DBT removal was unsatisfactory due to surface deactivation of the RVC electrode, which hindered its electrochemical activity toward DBT oxidation. To overcome this limitation, the electrode surface was modified with graphene as a surface modifier. The graphene coating improved charge transfer, provided additional active sites for reaction, and ultimately enhanced the overall process efficiency.
Performance evaluation of the modified electrode demonstrated that at an applied potential of 2.9 V and a reaction time of 2 hours, more than 93% of sulfur was removed from the model fuel containing approximately 1000 ppm of DBT. These results highlight the crucial role of graphene surface modification in preventing surface deactivation, improving stability, and enhancing electrochemical activity. Overall, it can be concluded that electrooxidative desulfurization in a biphasic system using a graphene-modified RVC electrode represents an efficient and effective method for the removal of sulfur compounds from model fuels.
