Chemical desulfurization of petroleum fractions for ultra-low sulfur fuels

An improved desulfurization process for removing sulfur from hydro treated diesel oil based on the oxidation of thiophenic type sulfur-containing compounds with H2O2 and acetic acid (AcOH) using H2SO4 as catalyst has been studied. The experimental results show that the sulfone content in the oxidation product increased rapidly with an increase in acetic acid and sulfuric acid ratios from 1:0 to 2:1 mole ratios. The maximum DBT conversion (wt.%) was at 2:1 mole ratio of acetic acid/sulfuric acid. This oxidation process is found to be capable of removing up to 90% of the sulfur compounds in hydro treated real fuels and can provide an alternative way to meet the future sulfur environmental requirements.Fifty eight sulfur-containing compounds were identified in hydro treated diesel sample. The sulfur compounds that have been identified in the hydro treated diesel include mainly refractory sulfur compounds (thiophenes and multi ring aromatic sulfur compounds, such as dibenzothiophene (DBT)). Sulfur species in typically hydro treated diesel and ring number distribution in 254–385 °C cut are also reported.