Review of Catalytic Hydrogen Generation in the DWPF Chemical Processing Cell, Part II

Koopman, David C.; Baich, M. A.

doi:10.2172/881529

Cited by 3 publications

(11 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Without mercury present (GF2), more hydrogen was generated by processing with the glycolic/formic flowsheet ( Figure 3-11). This is consistent with testing of the baseline flowsheet 23 . Hydrogen generation was slowly increasing near the end of reflux and appeared to plateau at a maximum of about 0.14 volume percent at the end of the SRAT cycle (peak hydrogen was 17 times higher in run without mercury than in GF3).…”

Section: Srat Hydrogen Suppressionsupporting

confidence: 86%

Glycolic-Formic Acid Flowsheet Final Report for Downselection Decision

Lambert¹,

Pickenheim²,

Stone³

et al. 2011

View full text Add to dashboard Cite

Section: Srat Hydrogen Suppressionsupporting

confidence: 86%

Glycolic-Formic Acid Flowsheet Final Report for Downselection Decision

Lambert¹,

Pickenheim²,

Stone³

et al. 2011

View full text Add to dashboard Cite

“…This conclusion differs from the single Ru test done along with the nitrite ion impact on Rh-catalyzed hydrogen study (BoleyLambert study) reported in the last major catalytic hydrogen review. 8 This conclusion is more The pH readings at 2.3 hours before the end of formic acid (onset of Ru dissolution) were 5.7 and 5.5 in the two runs. This pH range is both narrower than and consistent with the finding at 0.2 wt%.…”

Section: Wsrc-sti-2008-00002mentioning

confidence: 82%

Noble Metal Chemistry and Hydrogen Generation During Simulated DWPF Melter Feed Preparation

Koopman¹

2008

View full text Add to dashboard Cite

“…Some of the work at the University of Georgia, see the review in Koopman (2004a), as well as the 1998 data obtained by Boley and Lambert and analyzed in Koopman (2005b), point to a non-metallic phase of rhodium as potentially being more active, e.g. a rhodium complex in solution.…”

Section: Examination Of Differences In the Two Trimmed Noble Metal Runsmentioning

confidence: 99%

“…Update the review to cover Sludge Batch 3, SB3, and Sludge Batch 4, SB4, hydrogen generation data collected to date. The additional tasks are reported in Koopman (2005b).…”

Section: Overview Of Current Hydrogen Generation Programmentioning

confidence: 99%

“…Scoping work with the nitric acid sludge-only flowsheet has not shown a significant role for Ru. Koopman (2005b) has more details. Previously reviewed literature studies, Koopman (2004a), indicate that Pd should be the easiest noble metal to activate, and that it may be the most active of the three.…”

Section: Projected Direction Of Future Hydrogen Generation Studiesmentioning

confidence: 99%

See 1 more Smart Citation

DWPF Hydrogen Generation Study-Form of Noble Metal SRAT Testing

Bannochie¹

2005

View full text Add to dashboard Cite

EXECUTIVE SUMMARYThe Defense Waste Processing Facility, DWPF, has requested that the Savannah River National Laboratory, SRNL, investigate the factors that contribute to hydrogen generation to determine if current conservatism in setting the DWPF processing window can be reduced. A phased program has been undertaken to increase understanding of the factors that influence hydrogen generation in the DWPF Chemical Process Cell, CPC. The hydrogen generation in the CPC is primarily due to noble metal catalyzed decomposition of formic acid with a minor contribution from radiolytic processes. Noble metals have historically been added as trim chemicals to process simulations. The present study investigated the potential conservatism that might be present from adding the catalytic species as trim chemicals to the final sludge simulant versus co-precipitating the noble metals into the insoluble sludge solids matrix.Two sludge simulants were obtained, one with co-precipitated noble metals and one without noble metals. Co-precipitated noble metals were expected to better match real waste behavior than using trimmed noble metals during CPC simulations. Portions of both sludge simulants were held at 97°C for about eight hours to qualitatively simulate the effects of long term storage on particle morphology and speciation. The two original and two heat-treated sludge simulants were then used as feeds to Sludge Receipt and Adjustment Tank, SRAT, process simulations. Testing was done at relatively high acid stoichiometries, ~175%, and without mercury in order to ensure significant hydrogen generation. Hydrogen generation rates were monitored during processing to assess the impact of the form of noble metals. The following observations were made on the data:• Co-precipitated noble metal simulant processed similarly to trimmed noble metal simulant in most respects, such as nitrite to nitrate conversion, formate destruction, and pH, but differently with respect to hydrogen generation.The peak hydrogen generation rate occurred three to five hours later for the regular and heat-treated co-precipitated noble metal slurries than for the slurries with trimmed noble metals. The peak hydrogen generation rate was lower during processing of the co-precipitated noble metal simulant relative to the trimmed noble metal simulant data. Trimmed noble metals appeared to be conservative relative to co-precipitated noble metals under the conditions of these tests as long as the peak hydrogen generation rate occurred early in the SRAT boiling period.• If the peak hydrogen generation rate with trimmed noble metals is near or above the DWPF limit, and if the peak occurs late in the SRAT cycle, then a potential SME cycle hydrogen generation rate issue could be anticipated when using co-precipitated noble metals, since the peak is expected to be delayed relative to trimmed noble metals.• The peak hydrogen generation rate increased from about 1.3 to about 3.7 lbs H 2 /hr on the range of 170-190% stoichiometry, or about 0.1 lbs. H 2 /hr per % change in the...

show abstract

Review of Catalytic Hydrogen Generation in the DWPF Chemical Processing Cell, Part II

Cited by 3 publications

References 5 publications

Glycolic-Formic Acid Flowsheet Final Report for Downselection Decision

Glycolic-Formic Acid Flowsheet Final Report for Downselection Decision

Noble Metal Chemistry and Hydrogen Generation During Simulated DWPF Melter Feed Preparation

DWPF Hydrogen Generation Study-Form of Noble Metal SRAT Testing

Contact Info

Product

Resources

About