Nanocarbon materials for oxidative-adsorptive desulfurization using air oxygen under mild conditions

Anew oxidative-adsorptive desulfurization (OADS) process using graphene oxide (GO) and HNO3 modified carbon black (mCB) as adsorbents, and octanal-air as oxidation system was investigated under mild conditions in model fuel. GO was prepared by modified Hummer's method and characterized by X-ray diffraction (XRD), transition electron microscopy (TEM), scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR). In the OADS/Nanocarbon system, molar ratio of S and octanal, mass ratio of model fuel and nanocarbon, OADS temperature was optimized to be 24:1,200:1 and 60 degrees C respectively. High desuffurization uptakes of 45.1 and 45.4 mg-S/g-sorb were achieved under OADS system on GO and mCB, which are much higher than that under adsorptive desulfurization (ADS) system without in situ oxidation of dibenzothiophene (DBT). The desulfurization reactivity of various sulfur compounds in OADS system followed the order: Thiophene (TH)>DBT>4, 6-dimethyldibenzothiophene (4, 6-DMDBT)>Thianaphthene (BT) over GO, and 4, 6-DMDBT>THDBT> BT over mCB. Remarkably, 4, 6-DMDBT and TH could be effectively removed with the desulfurization efficiencies of 96.1% and 98.4%, respectively. The desulfurization capacity of GO could be completely regenerated in three recycles. (C) 2016 Elsevier B.V. All rights reserved.