Activated carbons (ACs) from olive stone were prepared using CO2, steam, KOH, and H3PO4 as activating agents. The resultant activated carbons were characterized by proximate and ultimate analysis, N2 adsorption (Brunauer-Emmett-Teller (BET) method), iodine number, Boehm titration, temperature-programmed desorption (TPD), and Fourier transform infrared spectroscopy (FTIR). Ammonia (NH3) was used as a test molecule to be adsorbed. The BET surface areas of the ACs obtained ranged from 1000 to 1986 m2 g-1. Type I isotherms were obtained for all the samples, although steam and H3PO4 ACs showed a significant mesopore contribution. KOH activation resulted in carbon with a high microporosity (98%) and high iodine adsorption (1030 mg g-1). KOH AC prepared with a KOH/pyrolyzed char weight ratio of 2 and at 900 °C showed the highest NH3 adsorption (252 mg g-1), favored by the high microporosity and adequate acidity. Chemical activation (KOH and H3PO4) promotes higher NH3 adsorption than the physical ACs prepared (CO2 and steam). Langmuir and Freundlich adsorption equilibrium models were used to correlate the NH3 adsorption isotherms, obtaining the best fit for the Freundlich equation. The results indicated that olive stone-based activated carbon could be used for commercial AC to remove NH3 from gaseous streams.

ABSTRACT The effect of supports and the addition of CS2 in the feed were studied on hydrodenitrogenation of Quinoline in a continuous flow reactor over ReS2/support catalysts at 300, 325 and 350 °C and 3MPa of H2. The ReS2 supported on TiO2 displayed the highest activity followed by ZrO2, γ-Al2O3 and SiO2 supports. The activity trend was correlated with the Re dispersion on the support. The effect of the addition of CS2 was increased activity until 2.5 v/v % content. At higher CS2 content the activity decreased due to competitive adsorption between CS2 and Quinoline on the active sites.

The influence of metal loading and support surface functional groups (SFG) on methane dry reforming (MDR) over Ni catalysts supported on pine-sawdust derived activated carbon were studied. Using pine sawdust as the catalyst support precursor, the smallest variety and lowest concentration of SFG led to best Ni dispersion and highest catalytic activity, which increased with Ni loading up to 3 Ni atoms nm-2. At higher Ni loading, the formation of large metal aggregates was observed, consistent with a lower "apparen" surface area and a decrease in catalytic activity. The H2/CO ratio rose with increasing reaction temperature, indicating that increasingly important side reactions were taking place in addition to MDR.