Radiative transfer in a solar chemical reactor for the co-production of hydrogen and carbon by thermal decomposition of methane

Radiation heat transfer in a solar chemical reactor for the co-production of hydrogen and carbon by thermal decomposition of CH4 is analyzed by the Monte Carlo ray-tracing method. The solar chemical reactor features a vortex flow of CH4 confined to a cavity and laden with carbon particles that serve simultaneously as radiant absorbers and nucleation sites for the heterogeneous decomposition reaction. The reactor is treated as a 3D non-isothermal non-gray absorbing-emitting-scattering gas/particle suspension directly exposed to concentrated solar irradiation. The analysis includes coupling to conduction/convection heat transfer and chemical kinetics. Calculated temperature distribution and chemical conversion are compared with the experimentally measured values obtained with a 5 kW prototype reactor tested in a solar furnace. (C) 2004 Elsevier Ltd. All rights reserved.