Investigation of methods for fuel desulfurization wastewater treatment

Today, fossil fuels are one of the primary energy sources, despite the growing use of renewable energy sources. Due to the increasing demand for energy and the sharp reduction of fossil fuels, the use of low-quality fossil fuel materials will be on the agenda. The combustion of low-quality liquid fuels causes an increase in SOx and NOx gases, as well as damages such as acid rain, breathing issues, destruction of industrial catalysts, etc. Due to increasing sulfur level restrictions in liquid fuels imposed in the last two decades, the use of conventional desulfurization and hydrogen desulfurization methods does not have the necessary efficiency, and it will also not be affordable due to high hydrogen consumption and tough operating conditions. Therefore, researchers have studied new methods such as hydrogen desulfurization, absorption, biological processes, extraction, and oxidation to achieve fuel with minimum sulfur compounds. Among these methods, oxidative desulfurization is often suggested as the most appropriate technique due to its mild performance and ease of separating oxidized sulfur compounds. This process involves the oxidation and removal of oxidized sulfur compounds from hydrocarbon fuels. Sulfones are removed from oxidized hydrocarbon fuels by various methods such as extraction, distillation, adsorption, decomposition, or a combination of these methods. The wastewater of this process, due to the high volume of solvent used in the removal stage of sulfur compounds from oxidized fuel, the presence of acid catalysts in the oxidation stage causes environmental problems. Therefore, wastewater treatment increases the ability to use this process on an industrial and semi-industrial scale. This study investigates wastewater treatment methods from the oxidative sulfur process.