Desulfurization studies of liquid fuels through nickel-modified porous materials from Pongamia pinnata

Abstract

Abstract A new biomass-based carbonaceous adsorbent has been developed from Pongamia pinnata and its effect upon nickel modification- and adsorption-coupled ultrasonication was investigated. Adsorption experiment of the model oil constituting 50 ppm dibenzothiophene in cyclohexane showed the maximum capacity as 8.11, 13.36, and 17.15 mg·g−1 for the commercial carbon DARCO, virgin bio-adsorbent PP, and nickel-modified adsorbent Ni@PP, respectively, with the time required for attaining equilibrium being the fastest in Ni@PP (120 min). The significant effect of ultrasonication was in attaining faster kinetics where ~ 96–98% removal was achieved in only 30 min. Also, the developed adsorbents had a very good specific surface area of 915 and 677 m2·g−1, respectively, for PP and Ni@PP. Investigation of the effect of higher initial sulfur concentration (200 ppm) indicated the significance of Ni modification, where a very high capacity of 66.18 mg·g−1 for Ni@PP was attained against 30.90 mg·g−1 for PP and 13.18 mg·g−1 for DARCO. Ni@ PP was also effective for the simultaneous removal of more refractory sulfur fractions from multicomponent model fuel systems and exhibited good regeneration ability till the fourth cycles or more. Cost estimation showed that the developed adsorbents are relatively ten times cheaper than commercial carbon, while the fixed-bed study indicated a breakthrough time of 250 min and 270 min for PP and Ni@PP, respectively. Graphic abstract