Stable isotope studies. Annual progress report, March 1, 1983-February 29, 1984

Technical Report · Mon Oct 31 04:00:00 EST 1983

OSTI ID:5682799

Ishida, T

The vapor pressure isotope effects (VPIE) between /sup 13/CH/sub 2/F/sub 2/ and /sup 12/CH/sub 2/F/sub 2/ and one between /sup 12/CD/sub 2/F/sub 2/ have been measured between 150 and 250/sup 0/K. The /sup 13/C//sup 12/C effect is inverse, and its magnitudes fall within a narrow difference between the /sup 13/C//sup 12/C-VPIE of methyl fluoride and fluoroform. The (normal) D/H-VPIE, however, shows magnitudes which are significantly higher than the D/H-VPIE's of methyl fluoride and fluoroform. In preparation for VPIE measurements of liquid and solid ammonia, /sup 14/NH/sub 3/, /sup 15/NH/sub 3/, and /sup 14/ND/sub 3/ samples have been purified against water, O/sub 2/, CH/sub 4/, N/sub 2/, and CO by using a combination of sodium treatment, distillation, and preparative GC. Impurity levels of the purified specimen are below 5 ppM for all impurities. The /sup 15/N fractionation column system based on the NO/N/sub 2/O/sub 3/ exchange, has been successfully operated under pressures up to 3 atm. The single stage separation factor (..cap alpha..) linearly increases with pressure, from 1.006 at 1 atm to 1.029 at 2.7 atm at 15.5/sup 0/C. The HETP slowly increases with decreasing concentration of +4 nitrogen which catalyzes the exchange reaction. However, the overall separation increases with pressure, from 1.5 at 1 atm to 4.0 at 2.7 atm. The closed-cycle product-reflexer for the Nitrox process, in which Fe/sup 2 +//Fe/sup 3 +/ solution in sulfuric acid is circulated between a product refluxer and electrolytic Fe/sup 2 +/-regeneration cells, has been studied to determine the extent of loss of enriched nitrogen in the refluxing system. The second-order orthogonal approximation for the zero-point energy (ZPE) has been refined, and new approximation parameters have been obtained.

• Research Organization: State Univ. of New York, Stony Brook (USA). Dept. of Chemistry
• DOE Contract Number: AC02-80ER10612
• OSTI ID: 5682799
• Report Number(s): DOE/ER/10612-9; ON: DE84002436
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400302* -- Organic Chemistry-- Isotope Effects-- (-1987)
400703 -- Radiochemistry & Nuclear Chemistry-- Radioisotope Production
CARBON 12
CARBON 13
CARBON ISOTOPES
CHALCOGENIDES
DEUTERIUM
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROGEN ISOTOPES
ISOTOPE EFFECTS
ISOTOPE SEPARATION
ISOTOPES
LIGHT NUCLEI
NITROGEN 15
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NITROGEN OXIDES
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RESEARCH PROGRAMS
SEPARATION PROCESSES
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
VAPOR PRESSURE