A novel desulfurization practice based on diesel acidification prior to activated carbon adsorption

Abstract

Commercial diesel is often rich with organosulfur compounds and a value of 7,100 mgS/kg was recently reported. As confirmed by chromatographic analysis, about 36% of sulfur compounds are originated from dibenzothiophene. Following uncommon desulfurization method, organosulfur compounds were efficiently removed upon diesel acidification by organic acids prior to activated carbon adsorption. Protonation of S-containing compounds has enhanced their uptake by activated carbon. Competitive adsorption of di/tri/tetra-aromatics and dibenzothiophene from synthetic fuel proved that the later solute was preferentially removed against other aromatics upon fuel acidification. Results showed that 48% of organosulfur compounds were eliminated upon adding acetic acid to a final content of 3% by vol. Principal component analysis indicated that acid content and carbon mass are the most significant factors on organosulfur compounds removal: %Removal=5.8 (Acid Content)+6.3 (Mass)-0.02 (PD)-0.90 (Temp). The practical efficiency of the proposed method was demonstrated by removing organosulfur compounds from commercial diesel.