(181f) Investigation of the Water Reduction with Zinc Powder Aerosol to Form Hydrogen Fuel

Hydrogen fuel can be generated by splitting water using thermo-chemical cycles and concentrated sunlight. One promising approach uses a two-step cycle with the Zn/ZnO redox system where ZnO is decomposed in the first step at temperatures above 1600 ^oC to form zinc metal and oxygen. In the second, low temperature step, the zinc metal reacts with water to form hydrogen and zinc oxide to close the cycle. Both reactions can be carried out with fine particles in an aerosol for continuous operation and fast reaction rates. The second, hydrogen forming step has been studied in a flow reactor at temperatures above 350 ^oC and residence times of few seconds using micron and sub-micron sized particles. The kinetics of this reaction will be presented and key challenges such as particle agglomeration and deposition inside the reactor will be discussed.