Evaluation of metal type in MIL-100 structure to synthesize a selective adsorbent for the basic N-compounds removal from liquid fuels

摘要

Negative effects of nitrogen-containing compounds (NCCs) on hydrodesulfurization catalyst activity and environmental demand are many efforts made to discover new methods for removing these compounds from fossil fuels. The adsorptive denitrogenation process can be an effective method if suitable adsorbents are used. In this study, three new metal-organic frameworks (MOFs), MIL-100 with different metal oxides (CrO3, Mn2O3 and V2O5) were synthesized and used as adsorbent in removing NCCs from a model fuel (iso-octane). Specific surface area (BET), X-ray powder diffraction patterns (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to investigate different characteristics of MIL-100 (Cr), MIL-100 (V) and MIL-100 (Mn). The ability of these adsorbents for NCCs removal from fuels was investigated by measuring the quinoline (QUI) adsorption capacity. The equilibrium data was defined well with the Langmuir isotherm and the adsorption kinetic data fitted fine to the first-second-order model. According to the obtained results, the maximum adsorption capacity of MIL-100 (Cr), MIL-100 (V) and MIL-100 (Mn) were 49.67, 68.90 and 54.05 (mg N/g adsorbent) at 20 degrees C, respectively. Also, selectivity of the synthesized MOFs for quinoline and dibenzothiophene (DBT) was studied at different temperatures and various times. Experimental results indicated that MIL-100 (V) has the highest quinoline/dibenzothiophene selectivity of 18 compared to MIL-100 (Mn) and MIL-100 (Cr) with the QUI/DBT selectivity of 13 and 12.