To predict the formation of nitrogen oxides in the heating system of coke plants, detailed information about the combustion process is needed. Due to the high temperature in the heating system, this data can not be measured. A model for a single combustion chamber was generated for the CFD program FLUENT 6.3 to simulate the formation of thermal and prompt NO in a pseudo-steady state. To prove the models ability to predict changes in the formation of NO due to different operating conditions, a set of simulations with typical operating conditions for a coke plant was generated and then compared to empirical values and literature.