We present a model that simulates the conventional tube-furnace experiment used for ignition studies. The Distributed Activation Energy Model of Ignition accounts for particle-to-particle variations in reactivity by having a single preexponential factor and a Gaussian distribution of activation energies among the particles. The results show that the model captures the key experimental observations, namely, the linear increase in ignition frequency with increasing gas temperature and the variation of the slope of the ignition frequency with oxygen concentration. The article also shows that adjustments to the model parameters permit a good fit with experimental data.