The present invention provides a method for carrying out high temperature thermal dissociation reactions requiring rapid-heating and short residence times using solar energy. In particular, the present invention provides a method for carrying out high temperature thermal reactions such as dissociation of hydrocarbon containing gases and hydrogen sulfide to produce hydrogen and dry reforming of hydrocarbon containing gases with carbon dioxide. In the methods of the invention where hydrocarbon containing gases are dissociated, fine carbon black particles are also produced. The present invention also provides solar-thermal reactors and solar-thermal reactor systems.
ACKNOWLEGEMENT OF GOVERNMENT SUPPORT
 This invention was made, at least in part, with funding from the United States Department of Energy under grant numbers DE-FC36-99G010454 and DE-AC36-99G010337. The United States Government has certain rights in this invention.