The HDS Process: Origin, Process Evolution, Reaction Mechanisms, Process Units, Catalysts and Health Risks

Sulfur content in crude oil varies between 1,000 and 30,000 ppm (parts per million), meaning its removal from fuels requires significant technical and economic effort. Growing concerns about pollution, accompanied by stricter environmental regulations, have led to the development of strategies to mitigate the negative effects of sulfur-containing compounds in petroleum, which can cause malfunctions in plants and refineries, such as catalyst poisoning in catalytic reforming equipment and sulfur dioxide emissions generated by the use of fuels in vehicles, vessels, furnaces, among others. Sulfur is one of the main pollutants in diesel and gasoline. The hydrodesulfurization method removes sulfur and nitrogen-containing compounds from diesel and gasoline, ensuring compliance with environmental regulations established for the import and export of fuels with concentrations below 8 ppm and 0.31 wt.% in diesel blends. In addition, it contributes to reducing sulfur dioxide and nitrogen dioxide emissions into the environment and prevents corrosion, which increases safety for both plants and end consumers.