ABSTRACT
The increasing use of fossil fuels is polluting the environment at a constantly increasing rate. Besides carbon dioxide, a greenhouse gas, the use of petroleum and its fractions generates signi- cant quantities of sulfur oxides (SOx), which play a major role in the formation of acid depositions. Thus, reneries are facing many challenges, including the inux of heavy crude oils, increased fuel quality standards in terms of a severely diminished and regulated sulfur content, and the need to reduce all forms of emissions to meet air pollution regulations. In fact, environmental regulations in every country worldwide are becoming more stringent in order to reduce all forms of emissions, including that of sulfur oxides. Furthermore, as the global community moves toward zero-sulfur fuels, the only differences are the starting point of sulfur level (feedstock sulfur) and rate reduction of sulfur content during renery operations. To meet these more stringent regulations, high-quality crude oil with low sulfur content is preferred; however, when not available, the only alternative option is to remove sulfur during the rening process.
