High-density conversion of light energy via direct illumination of catalyst

Abstract

Steam reforming of methane was studied under direct illumination of a catalyst by concentrated light in the energy receiver/reactor with a transparent wall. In such a reactor, both the specific rate of hydrogen production and the specific power loading of the light-to-chemical energy conversion appear to increase considerably with respect to a conventional stainless steel reactor, reaching 130 Ndm 3/h per 1 g of the catalyst and 50–100 W/cm 3, respectively. No considerable photochemical enhancement of the reaction rate was observed. The increase in the reaction rate is supposed to be caused by a significant intensification of energy supply into the catalyst bed due to absorption of light directly by granules of the catalyst used. Moreover, the transparent reactor also showed a higher efficiency of energy conversion because the temperature of the illuminated quartz wall appears to be lower than that for a steel wall which results in lower heat losses. This evidences in clear potentialities of a new generation of “volumetric” solar energy receivers/reactors.