Catalyst for ultra-low sulfur and aromatic diesel

A WNiPd/TiO2·Al2O3 new catalyst with improved desulfurization and hydrogenating capabilities was tested to produce ultra-low sulfur and aromatics diesel oil. The removal of the sterically hindered sulfur and nitrogen containing polyaromatic molecules is studied. It was observed that the new catalyst surface structure promotes the hydrogenating and ring opening of poly-alkyl-poly-aromatics that are less limiting step than that with conventional catalyst. The catalyst characterization indicated the possible formation of metallic acid sites that contribute to the ring opening reactions. The catalyst study using the extracted aromatics and the raffinated product indicated a large improvement in hydrogenation and a reduction in hydrodealkylation functions for converting these sterically hindered aromatics. The reduction in aromatics families improves diesel engine emissions.