Selective adsorption of nitrogen compounds using silica-based mesoporous materials as a pretreatment for deep hydrodesulfurization

• Published in: Catalysis today 2018-05, Vol.305, p.40-48
• Main Authors: García-Martínez, J.C., González Uribe, H.A., González-Brambila, M.M., Colín-Luna, J.A., Escobedo-García, Y.E., López-Gaona, A., Alvarado-Perea, L.
• Format: Article
• Language: English
• Subjects: Adsorption; Diesel; Hydrodesulfurization; Langmuir; Ultra-low sulfur diesel
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2017.10.037

Adsorption isotherms of nitrogen using a) SBA-15, b) SBA-16, and c) MCM-41. Symbols correspond to experimental data; dashed lines are fitted to the Langmuir isotherm and solid lines to the Freundlich isotherm. [Display omitted] •Mesoporous materials were tested in the adsorption of nitrogen- and sulphur-containing compounds at room temperature and atmospheric pressure.•All mesoporous materials used adsorbed preferentially nitrogen compounds than sulfur compounds.•It is postulated that the adsorption difference in the SBA-15, SBA-16 and MCM-41 is related to the specific area of the materials.•MCM-41 revealed better adsorption capacity than SBA-15 and SBA-16 for the adsorption of nitrogen compounds. The adsorption of quinoline (Q) and dibenzothiophene (DBT)—model compounds for nitrogen and sulfur in diesel fuels—over mesoporous SBA-15, SBA-16, and MCM-41 was studied. The Langmuir model was suitable for describing the adsorption of nitrogen-containing compounds from a simulated diesel fuel. A pseudo-second-order kinetic model better fitted the Q adsorption data than a first-order rate model when describing the adsorption rates on all materials. Comparison of the adsorption of Q and DBT confirmed that the nitrogen compound was selectively removed, and MCM-41 was found to have better adsorption characteristics than SBA-15 and SBA-16. DBT was not adsorbed in any experiment. The adsorbents were characterized using N2-physisorption, powder X-ray diffraction, and high-resolution transmission electron microscopy to describe the morphologies of the adsorbents. The characterization results revealed that the specific area and the structure of the adsorbent are key parameters required to explain the adsorption process.