Performance Investigation of the Solar Thermal Decomposition of Methane Reactor Considering Discrete and Deposited Carbon Particles

In this study, a dynamic Eulerian-Lagrangian framework combined with porous media model was developed to simulate the performance variations of a tubular methane decomposition reactor, including its deposition rate, methane conversion, yields of hydrogen and carbon particles. The particle behaviors including their nucleation, trajectory, heat radiation, growth due to heterogeneous reaction, collision and deposition at the reactor wall were taken into account. The numerical model employed multi-step reaction mechanism and accounted for the two-way coupling between continuous phase and carbon particles. Simulation results of both continuous phase and discrete phase were compared with experiment results and other TDM models. It was suggested that the TDM reaction accelerated with the formation of carbon particles and deposits. There were significant variations of the local particle size distribution across the reactor due to the existence of boundary layer and the uneven temperature field. And the causes of carbon plug formation, increasing the flow resistance and eventually lowering the life of reaction tube, were discussed