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Gasification is an attractive method to convert lignocellulosic biomass into a combustible gas mixture for electricity and power generation. To control the tar concentration in the produced gas to be within the allowable limit of downstream applications, it is important for a gasification system to be integrated with a tar removal process. In this study, an integrated gasification system consisting of a downdraft gasifier and a secondary catalytic tar‐cracking reactor was designed and tested for the gasification of pelletized oil palm empty fruit bunch. To further purify the producer gas, the system was also integrated with a cyclone, a water scrubber, and a carbon‐bed filter. Biomass was fed at a rate of 5 kg/h, while the air equivalence ratio (ER) and the gasification temperature were set at 0.1 and 800°C, respectively. In total, 5 kg of the specially developed low‐cost Fe/activated carbons (AC) catalyst was used in the hot gas catalytic tar‐cracking reactor. Results indicate that our integrated gasification system was able to produce a clean burnable gas with a lower heating value (LHV) of 9.05 MJ/Nm3, carbon conversion efficiency (CCE) of 79.4%, cold gas efficiency (CGE) of 89.9%, and H2 and CH4 concentrations of 29.5% and 10.3%, respectively. The final outlet gas was found to only contain 32.5 mg/Nm3 of tar, thus making it suitable for internal combustion engine (ICE) application. [ABSTRACT FROM AUTHOR]

A kinetic investigation on the reduction of nanometer-sized nickel oxide particles (supported and unsupported) with hydrogen was carried out. The reduction behavior was found to be related to the average size of NiO crystallites. When the NiO crystallite size was less than about 20 nm, the dissociation of H2 was the key rate-limiting factor and remained unchanged almost throughout the reduction process. However, when the NiO crystallite size was >20 nm, its reduction kinetics changed with conversion, showing two kinetic compensation effects at lower and higher NiO conversion levels. It is believed that the movement and rearrangement of H atoms inside such bulk Ni/NiO solid could be an important aspect of the reduction kinetics, especially at higher (50%-90%) NiO conversion levels. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 667-676, 2011 [ABSTRACT FROM AUTHOR]

A kinetic investigation on the reduction of nanometer-sized nickel oxide particles (supported and unsupported) with hydrogen was carried out. The reduction behavior was found to be related to the average size of NiO crystallites. When the NiO crystallite size was less than about 20 nm, the dissociation of H2 was the key rate-limiting factor and remained unchanged almost throughout the reduction process. However, when the NiO crystallite size was >20 nm, its reduction kinetics changed with conversion, showing two kinetic compensation effects at lower and higher NiO conversion levels. It is believed that the movement and rearrangement of H atoms inside such bulk Ni/NiO solid could be an important aspect of the reduction kinetics, especially at higher (50%-90%) NiO conversion levels. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 667-676, 2011 [ABSTRACT FROM AUTHOR]