ABSTRACT
With an increased environmental demand for cleaner burning fuels, a decrease in S and N contents of fuels is required. Burning of N compounds was reported to contribute to acid rain and greenhouse effects. The literature reports on the use of different methods to desulfurize fuels. The literature reviewed the selective removal of sulfur compounds from petroleum products using ionic liquids. Ionic liquids are salts, containing cationic quaternary nitrogen, which melt below room temperature (Aslanov and Anisimov, 2004). The literature reported on the efficiency of different methods, such as hydrochloric acid extraction, liquid-solid adsorption, and complexation, to remove basic nitrogen (BN) compounds from gasoline. Under the optimum conditions over 90% of BN can be removed (Feng, 2004). The literature reported on the desulfurization of middle distillates by an oxidation and extraction process. The oxidation was carried out using hydrogen peroxide and acetic acid as a catalyst. The extraction of sulfones was carried out using different polar solvents, such as acetonitrile, methanol, 2-ethoxyethanol, and g-butyrolactone (Ramirez-Verduzco et al., 2004). The literature also reported on the use of hydrogen peroxide and sulfuric acid solutions for the removal of sulfur from fuel oil (Karaca and Yildiz, 2005). The optimum oxidation condition, such as a hydrogen peroxide concentration of 15 wt%, a temperature of 408C, and a time of 60-50 min, was needed to desulfurize fuel oils (Yildiz and Karaca, 2005). The aromatic and heteroatom content of different light oils is shown in Table 11.1.
