The formation of ammonia in gasified gases produced from coal or biomass poses a problem in that, as with any fuel, the nitrogen components are partially converted to NO during combustion in a gas turbine. In this paper, one of the options available for the reduction of ammonia in the gases, namely the injection of gaseous reactants such as NO and oxygen in a well mixed gas-phase reactor, is examined. The predicted equilibrium stability of ammonia in the synthesis gas occurs at similar to750 K at atmospheric pressure; this peak maximum shifts to similar to1000 K at 20 bar pressure. Higher temperatures favour the destruction of ammonia. Therefore, one hypothesis tested was oxidant injection at temperatures in excess of 1100 K followed by cooling. The gasification gases frequently contain methane and chemical reaction modelling techniques have been used to consider the options available particularly in this case. None of the models provided a satisfactory solution to this problem. Because of the methane in the gases, HCN is a reaction product, so that the total amount of fuel-nitrogen compounds is not reduced to a sufficiently low level for gas turbine applications.