The burning process of a single carbon particle in air at isobaric conditions is studied. Transient numerical simulations, including detailed physical and chemical models, are performed. The characteristic values of the burning process, i.e., the burning rate and the surface temperature, show an unsteady behavior. However, if the particle radius is fixed artificially, a steady behavior of these values can be observed. Furthermore, it turns out that if the ambient temperature is sufficiently high, the d(2)-law holds and the burning rate constant K (of the d(2)-law) is almost constant in time. Thus, the burning process bears a strong resemblance to the transport controlled regime. These findings are confirmed by the obtained results of a minor dependence of the burning rate on the ambient pressure and an almost linear dependence of the burning rate on the oxygen concentration in the ambient gas phase. (C) 2009 Elsevier Ltd. All rights reserved.