This paper examines the effects of different operating variables on cupric chloride (CuCl(2)) powder formation in a copper-chlorine (Cu-Cl) thermochemical cycle of hydrogen production. Experiments have been performed in two different spray drying units to identify the effects of the main operating variables on the cupric chloride powder quality. The experiments also examine the formation of powders using low temperature heat available from nuclear, solar and other industrial sources to remove moisture from solutions. The atomization liquid flow rate, atomization pressure and drying air inlet temperature are identified as independent variables. The moisture content, bulk density, particle size distribution and morphology are the dependent variables representing the powder quality. Experimental data have been analyzed for cohesive force and free flow characterization of powders using the Hausner ratio. Copyright (C) 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.