A solar-thermal aerosol flow reactor has been constructed, installed, and tested with the High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL). Experiments were successfully carried out for the dissociation of methane to produce hydrogen and carbon black and for the dry reforming of methane with carbon dioxide to form syngas (hydrogen and carbon monoxide). Approximately 90% dissociation of methane was achieved in a 25-mm diameter quartz reaction tube illuminated with a solar flux of 2400 kW/m(2) (or suns). The carbon black produced was amorphous and had a particle size of 20 to 40 nm. Approximately 70% conversion was achieved for dry reforming using a solar flux of 2000 kW/m(2). The experimental results for both processes are very encouraging and support further work to address the technical issues and to develop the processes.