Combustion is an extremely important process in several industries, serving both to generate energy or to burn gases that are harmful to the environment such as methane. During combustion, the phenomenon known as flashback can occur, where the flame propagates upstream into the tube. This phenomenon may cause material damage if the flame returns to the pipelines because the gas transport equipment is not designed to withstand the high temperatures and pressures that combustion implies. In recent studies, mesh adaption are developed based on temperature gradient for simulation of combustion process. Detailed chemical kinetics has been used in more recent analyzes to better describe the chemical reaction. Influence of parameters such as mixing speed and equivalence ratio are analyzed with adiabatic and isothermal wall boundary conditions for flashback verification. The present work is aimed at the analysis of pre-mixed methane-air flames when flashback occurs in circular tubes. At the beginning of the simulation it is applied a determined temperature profile to supply the necessary energy to start the combustion and a speed profile of the Poiseuille flow in the entrance of the domain. The solved equations are those of ideal gas, continuity, momemtum, species and energy. Two thermal boundary conditions on the wall are analyzed, adiabatic and isothermal. As combustion occurs, mesh adaption based on the temperature gradient is performed. Adaption is performed to better describe the fastest chemical reactions, which does not occur in a coarser mesh. The results show that the temperature profile inside the tube for the adiabatic and isothermal walls differ due to heat exchange. It was also observed that the average flow velocity needs to be greater than the speed of the flat flame so that flashback is prevented.