Catalytic combustion of gasified refuse-derived fuel

The catalytic combustion of gasified refuse-derived fuel (RDF), i.e. a low heating-value (LHV) gas containing H2, CO and CH4 as combustible components, has been studied and compared with the combustion of methane. Two metal oxide catalysts, i.e. a spinel and a hexaaluminate, and three noble metal catalysts were tested. The results show that the Pd-based catalysts were the most active both for the gasified waste, i.e. RDF and methane. Incorporating an active support such as LaMnAl11O19 enhances the catalytic activity for methane in gasified waste. Substituting Mn into the crystal lattice of the spinel also increased the catalytic activity for H2 and CO, while the methane activity remained low. The formation of NOX from fuel-bound nitrogen was investigated by adding NH3 to the gas stream. The metal oxide catalysts showed a higher selectivity for oxidising NH3 into N2 than the catalysts containing precious metals. The spinel materials have high thermal stability and are comparable to the hexaaluminates confirming that they could be promising as washcoat materials to avoiding sintering at high temperatures.