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Kinetics and transport phenomena in the chemical decomposition of copper oxychloride in the thermochemical Cu-CI Cycle

The thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production
includes three chemical reactions of hydrolysis, decomposition and electrolysis. The
decomposition of copper oxychloride establishes the high-temperature limit of the cycle.
Between 430 and 530 oC, copper oxychloride (Cu2OCl2) decomposes to produce a molten
salt of copper (I) chloride (CuCl) and oxygen gas. The conditions that yield equilibrium at
high conversion rates are not well understood. Also, the impact of feed streams containing
by-products of incomplete reactions in an integrated thermochemical cycle of hydrogen
production are also not well understood. In an integrated cycle, the hydrolysis reaction
where CuCl2 reacts with steam to produce solid copper oxychloride precedes the
decomposition reaction. Undesirable chlorine may be released as a result of CuCl2
decomposition and mass imbalance of the overall cycle and additional energy
requirements to separate chlorine gas from the oxygen gas stream.
In this thesis, a new phase change predictive model is developed and compared to
the reaction rate kinetics in order to better understand the nature of resistances. A Stefan
boundary condition is used in a new particle model to track the position of the moving
solid-liquid interface as the solid particle decomposes under the influence of heat transfer
at the surface. Results of conversion of CuO*CuCl2 from both a thermogravimetric (TGA)
microbalance and a laboratory scale batch reactor experiments are analyzed and the rate of
endothermic reaction determined. A second particle model identifies parameters that
impact the transient chemical decomposition of solid particles embedded in the bulk fluid
consisting of molten and gaseous phases at high temperature and low Reynolds number.
The mass, energy, momentum and chemical reaction equations are solved for a particle
suddenly immersed in a viscous continuum. Numerical solutions are developed and the
results are validated with experimental data of small samples of chemical decomposition
of copper oxychloride (CuO*CuCl2). This thesis provides new experimental and
theoretical reference for the scale-up of a CuO*CuCl2 decomposition reactor with
consideration of the impact on the yield of the thermochemical copper-chlorine cycle for
the generation of hydrogen. / UOIT

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OOSHDU.10155/258
Date01 April 2012
CreatorsMarin, Gabriel D.
ContributorsNaterer, Greg F., Gabriel, Kamiel
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeDissertation

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