Photothermal Oxidative Destruction of Chloronaphthalene

We have investigated the feasibility of using concentrated solar photons for the destruction of hazardous waste. Chloronaphthalene was chosen as the model compound for study, and light intensities were used that are close to those expected from a high-flux solar furnace. The results showed that the addition of ultraviolet photons to a reactor greatly accelerates the reaction rate for oxidation. The light intensity has an exponential effect on the degree of destruction, as predicted by earlier studies. Derived primary quantum yields in the gas phase are much higher than reported values in organic liquids: 0.2 for gas phase vs 0.002–0.005 for liquids. The products of incomplete oxidation were tentatively identified, and similar products were found in the presence orabsence of ultraviolet light. At low temperatures, the ultraviolet light appeared to promote the formation of these products, while at higher temperatures, the light enhancedthe destruction of the byproducts. It was found that, at a given destruction level, th product slate was similar with and without the light.