Thermal coupling of methane was investigated in a tubular flow reactor in the temperature range 1200-1500-degrees-C at atmospheric pressure. The main products observed were ethane, ethene, ethyne, benzene and "coke". A mechanistic simulation model was developed for this process. The kinetic scheme consists of 32 reversible free radical reactions and one irreversible free radical reaction. The model data provide good agreement with experimental data for the conditions being studied. A sensitivity analysis was used to find the main free radical reactions in the formation and consumption of the reported products.