Study On Desulfurization Over Nickel-based Adsorbents

Due to the increasingly stringent environmental regulations on sulfur concentration in transportation fuels, the adsorption desulfurization of fuel oil has become a more and more important research subject.The nickel-based sorbents were synthesized by the sol-gel and the hydrothermal methods using chitosan(CS) of different degrees of deacetylation(DD) and different concentration as the template. This article investigated the adsorptive capacity of the sorbents for desulfurization of model gasoline at 25℃. The sorbents were characterized by means of thermo-gravimetric(TG),X-ray diffraction(XRD), N2 adsorption isotherm(BET and pore-size distribution) and Fourier transform infrared(FT-IR) techniques , etc.The research indicated that when the sobent was synthesized without the template, the sobent was anafase with the specific surface area of 24m~2/g, the average pore size of 24.066nm and the average pore volume of 0.147cm~3/g. When the sorbents were synthesized using CS as the template , the specific surface area of sorbents was from 40m~2/g to 99m~2/g; the average pore size was from 17.75nm to 9.18nm; the average pore volume was from 0.150cm~3/g to 0.286cm~3/g.Firstly, we investigated the adsorptive capacity of the sorbents for desulfurization of model gasoline with octane and thiophene (sulfur concentration is 800mg/L). When the sobent was synthesized without the template, the largest adsorptive capacity of the sorbents was 21.84mg/g. While the sorbents were synthesized by the sol-gel method using CS as the template, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was 26.3mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 28.3mg/g. While the sorbents were synthesized by the hydrothermal method, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was 25.94mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 29.45mg/g.Secondly, we studied the adsorptive selectivity of thiophene and quinoline (nitrogen concentration is 350mg/L). When the sobent was synthesized without the template, the largest adsorptive capacity of the sorbents was 9.98mg/g. While the sorbents were synthesized by the sol-gel method using CS as the template, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was 24.82mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 24.43mg/g. While the sorbents were synthesized by the hydrothermal method, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was 23.97mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 26.05mg/g. In addition, we studied the adsorptive selectivity of thiophene and naphthalene (nap concentration is 3204.5 mg/L). When the sobent was synthesized without the template, the largest adsorptive capacity of the sorbents was 6.43mg/g. While the sorbents were synthesized by the sol-gel method using CS as the template, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was 25.02mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 25.44mg/g. While the sorbents were synthesized by the hydrothermal method, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was 25.65mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 26.14mg/g.Thirdly, we studied the adsorptive selectivity of thiophene, quinoline and naphthalene. When the sobent was synthesized without the template, the largest adsorptive capacity of the sorbents was 5.50mg/g. While the sorbents were synthesized by the sol-gel method, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was 23.71mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 24.86mg/g. While the sorbents were synthesized by the hydrothermal method, if the DD of CS is 88%, the largest adsorptive capacity of the sorbents was23.79mg/g; if the DD of CS is 59%, the largest adsorptive capacity of the sorbents was 25.63mg/g.