Hydrolysis of Evaporated Zn in a Hot Wall Flow Reactor

Abstract

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 1023K and 1073K. 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 800Kto1077K.