Revisão dos métodos alternativos à hidrodessulfurização do diesel: desafios e perspectivas

Abstract

Combustion of petroleum products, such as diesel, releases NOx, SO2 gases and particulate matter, causing air pollution, acid rain and damaging human health. In view of this, environmental legislation is increasingly tightened on the permitted sulfur content of liquid fuels. Hydrodesulfurization (HDS) is the method commonly used by refineries to treat diesel. This method is effective in removing non-aromatic sulfur compounds, such as mercaptans, sulfides and disulfides. However, it is ineffective for the removal of heterocyclic aromatics, such as benzothiophenes (BT) and dibenzothiophenes (DBT). For this reason, alternative methods to HDS have been developed and studied. Among them, we can highlight extractive desulfurization (EDS), oxidative desulfurization (ODS), adsorptive desulfurization (ADS) and biodesulfurization (BDS). In the present study, a literature review of the cited methods was carried out. From the works reviewed, it was possible to note that all showed potential for the ability to desulfurize the diesel, but also presented several limitations. For ODS, EDS and ADS it is suggested that these methods have better efficiency if used as a complement to the hydrodesulfurization. So far, none of them are being applied commercially.