DWPF Catalytic Hydrogen Generation Program - Review of Current Status

Elimination Of Catalytic Hydrogen Generation In Defense Waste Processing Facility Slurries

“…The reaction sequence is laid out in a later technical report (page 35 of 48). 6 High concentrations of nitrite ion prevent the ligand exchange and prevent hydrogen generation. At 0.2 wt.% Rh in the total slurry solids (higher than in any DWPF sludge batch to date), nitrite had to fall to <200 mg/kg slurry before detectable evidence for hydrogen generation was found.…”

Sludge Characterization and Srat Simulations Using a Nitrite-Free Sludge Simulant

“…These findings also address one of the issues raised in the Future Work section of the recent summary document concerning catalytic hydrogen generation in the CPC. 1 The knowledge gained should facilitate planning future experiments.…”

“…As discussed in the catalytic hydrogen generation status report, a growing body of evidence had been accumulated that tended to support the concept of a nitro-Rh complex as the primary active form of rhodium for hydrogen production. 1 Rhodium-based production of hydrogen was detected at low nitrite ion concentrations near the end of nitrite destruction. The primary peak due to rhodium seemed to end as nitrite destruction went to completion.…”

“…These conclusions were presented in a recent status summary report, which includes references that lead to most relevant prior work on the subject. 1 The maximum hydrogen generation rate in the SRAT often occurred near the end of nitrite destruction and was correlated with the Rh concentration. Some simulations, however, had a greater maximum hydrogen generation rate occur after nitrite destruction which was due to a catalytic contribution from Ru that exceeded the maximum hydrogen generation rate due to Rh.…”

“…The analysis of the experimental data led to a few questions that were included as areas for future work in the status summary report: 1 First, Ru seemed to go through a transitional form based on solubility data before the catalytically active form for hydrogen generation appeared. The identity of both forms remains unknown.…”