Hydrolysis of evaporated Zn in a hot wall flow reactor

Hydrolysis of Zn is investigated as the second step in a ZnO/Zn redox solar water splitting process. Zinc is evaporated and hydrolyzed with steam in a hot wall flow tubular reactor. The influence of the reactor temperature distribution and residence time on hydrogen conversion was measured for furnace set point temperatures of 1023 K and 1073 K. The yield of ZnO aerosol was measured in situ using a scanning differential mobility sizer. The composition and morphology of the solid product were characterized with X-ray diffraction and microscopy. Hydrogen conversions of 87-96% at temperatures above zinc saturation are attributed primarily to hydrolysis of zinc(g) at the wall of the reactor at temperatures from 800 K to 1077 K.