Solar-Thermal Reactor Engineering - the Ultimate in Process Intensification

High-temperature solar-thermal reactor engineering has been a focus at the University of Colorado for over a decade. Three generations of solar reactors have been developed and demonstrated on-sun in the High-flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL). Reaction temperatures exceeding 1000 deg C are achieved using concentrated sunlight.

Among the processes being developed are the production of syngas from biomass gasification, the dissociation of methane to produce hydrogen and carbon black, and various metal oxide reduction reactions as the high-temperature step in multi-step thermochemical water-splitting cycles.

This paper will review the fundamental thermodynamic considerations for solar-thermal processing and recent results for the rapid conversion of biomass by pyrolysis and gasification. The process provides for a higher yield of syngas from biomass compared to conventional thermochemical gasification, an increase in the heating value of the product sygnas vs. the starting biomass and a significant reduction/elimination of tar formation.

Solar field design will also be presented – i.e. mirror array, tower height, reactor materials and design considerations. A particular emphasis will be placed on identifying critical issues that need overcome to commercialize the process.