The enhanced adsorption of sulfur compounds onto mesoporous Ni-AlKIT-6 sorbent, equilibrium and kinetic analysis

High performance nickel supported on mesoporous AlKlT-6 (Si/AI = 15, 25, 50, 100) sorbents were prepared by incipient wetness impregnation (IWI) with ultrasonic aid for adsorptive desulfurization of commercial diesel and simulated fuels. The sorbents were characterized by N-2 adsorption-desorption, XRD, NH3-TPD, Py-FT-IR, HRTEM, SEM and atomic absorption spectroscopy techniques. The analysis results confirmed that Aluminum atoms entered the framework and 20%Ni-AlKlT-6(15) can still retain three dimensional structure of AlKIT-6(15) and Ni is highly dispersed in the support. The kinetic pseudo second-order model and Langmuir isotherm are shown to exhibits the best fits of experimental data for the adsorption of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over AlKlT-6 and 5-30%Ni-AlKlT-6. Intraparticle diffusion and steric hindrance were the rate controlling step of the adsorption of T and DBT over AlKlT-6(15) and 20%Ni-AlKlT-6(15) as verified through the intraparticle diffusion model. The characterization of regenerated 20%Ni-AlKlT-6(15) revealed that three-dimensional cubic Ia3d symmetric structure was maintained in the sorbent after 6 successive desulfurization-regeneration cycles. (C) 2014 Elsevier B.V. All rights reserved.