Denitrogenation of raw diesel fuel by lithium-modified mesoporous silica

Lithium-modified mesoporous silica adsorbents (YSP-Li and MCF-Li) were prepared in order to selectively remove nitrogen compounds from residue hydrodesulfurization diesel (RHDS DSL: 271.3 ppmw of nitrogen compounds and 430.2 ppmw of sulfur compounds) provided by a refinery factory. Adsorption properties, such as the adsorption capacity, adsorption rate, and the regeneration ability toward nitrogen and sulfur compounds, were measured through batch experiments at 15 and 45 °C. They were compared with the results of previously reported Si–Zr cogel experiments. The lithium-modified mesoporous silica adsorbents exhibited a much stronger adsorption affinity for nitrogen compounds than for sulfur compounds. With regards to the adsorption capacity and the adsorption rate, the lithium-modified mesoporous silica adsorbents exhibited improved performance when compared to Si–Zr cogel. Furthermore, the Li-modified adsorbents, especially YSP-Li, could be easily regenerated by MIBK, an organic solvent.