Modeling of temporal behavior of isotopic exchange between gaseous hydrogen and palladium hydride power

Technical Report · Thu Jan 01 04:00:00 EST 1987

DOI:https://doi.org/10.2172/6720738· OSTI ID:6720738

Melius, C F; Foltz, G W

A parametric rate-equation model is described which depicts the time dependent behavior of the isotopic exchange process occurring between the solid and gas phases in gaseous hydrogen (deuterium) flows through packed-powder palladium deuteride (hydride) beds. The exchange mechanism is assumed to be rate-limited by processes taking place on the surface of the powder. The fundamental kinetic parameter of the model is the isotopic exchange probability, p, which is the probability that an isotopic exchange event occurs during a collision of a gas phase atom with the surface. Isotope effects between the gas and solid phases are explicitly included in terms of the isotope separation factor, ..cap alpha... Results of the model are compared with recent experimental measurements of isotope exchange in the ..beta..-phase hydrogen/palladium system and, using a literature value of ..cap alpha.. = 2.4, a good description of the experimental data is obtained for p approx. 10/sup -7/. In view of the importance of the isotope effects in the hydrogen/palladium system and the range of ..cap alpha.. values reported for the ..beta..-phase in the literature, the sensitivity of the model results to a variation in the value of ..cap alpha.. is examined.

• Research Organization: Sandia National Labs., Livermore, CA (USA)
• DOE Contract Number: AC04-76DR00789
• OSTI ID: 6720738
• Report Number(s): SAND-86-8244; ON: DE87007162
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
DEUTERIDES
DEUTERIUM
DEUTERIUM COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPE EFFECTS
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
NUCLEI
ODD-ODD NUCLEI
PALLADIUM COMPOUNDS
PALLADIUM HYDRIDES
STABLE ISOTOPES
TRANSITION ELEMENT COMPOUNDS