Reaction kinetics and product evolution of hydrolysis in copper-chlorine thermochemical cycle for hydrogen production

By-products of the hydrolysis reaction in the copper-chlorine thermochemical cycle for hydrogen production are key to the final thermal and hydrogen efficiency. The current study focuses on the influences of reaction time, temperature, and steam partial pressure on the hydrolysis reaction and by-product formation mechanism via experimental and multiple analytical methods. The result demonstrates that the hydrolysis reaction of CuCl 2 and steam converts to CuCl and Cu 2 OCl 2 , with a high conversion of 97%, while the Cu 2 OCl 2 and CuCl 2 -CuO product mixtures exhibit interconversion capabilities. The increase of temperature increases the CuCl product content, while the decrease of steam partial pressure increases the by-product CuCl 2 . Particle morphology and reaction thermodynamics are analyzed for main and by-products formation. Finally, the homogeneous reaction model and shrinking core model are used and compared for the activation energy of the formation of Cu 2 OCl 2 for the hydrolysis reaction and the effect of by-products.