Traditional Ni/YSZ anode SOFCs were modified by Sn, Cu and Ag by an infiltration method to obtain Sn-Ni, Cu-Ni and Ag-Ni alloy anode catalysts on the anode. The obtained maximum power density of Ni/YSZ, Sn-doped Ni/YSZ, Cu-doped Ni/YSZ, and Ag-Ni/YSZ cells fuelled by simulated biogas (14 mL min⁻¹ CH₄, 7mL min⁻¹ CO₂ and 7mL min⁻¹ N₂) at 750°C were 0.101, 0.272, 0.085 and 0.102 W cm⁻² respectively. Stability tests of SOFCs in biogas revealed that the stability of Sn-Ni/YSZ and Ag-Ni/YSZ cells in operation was greatly improved compared to the undoped Ni/YSZ cell. Both Sn-Ni/YSZ and Ag-Ni/YSZ cells stably operated for 48 h, but Ni/YSZ cell ceased operation after 19 h due to carbon deposition. The addition of small amount of Cu did not enhance the anti-coking ability. Other than with the severe carbon deposition on the Ni/YSZ anode surface, no observable fibrous carbon could be identified on the Sn-Ni/YSZ and Ag-Ni/YSZ anode surfaces.

In this study, Malaysian dolomites as secondary catalysts are placed at the downstream of the fluidized-bed gasifier. Three types of Malaysian dolomites with different elemental ratios of CaO-MgO content denoted as P1, P2, and P3 are investigated with EFB gasification reaction at different cracking temperatures (700–900 °C). The performance of the catalysts with a variation of catalyst to biomass weight ratio (C/B) (0.05 to 0.30 w/w) is evaluated. The findings showed that the total gas yield increased by 20%, hydrogen increased by 66%, along with an almost 99% reduction in tar content with P1 catalyst with the following reaction conditions: gasification temperature of 850 °C, equivalence ratio (ER) of 0.25, and cracking temperature of 900 °C. Malaysia dolomite could be a secondary catalyst to provide a better alternative, tar-free hydrogen-rich gas with the possibility of regeneration and re-use.