Determination of TCAP (Thermal Cycling Absorption Process) Raffinate Purity
Xin Xiao, Henry T. Sessions, Ben Randall, Joshua Cooper, Lucas Angelette, Michael Brown, Hope Hartman, Dave Babineau
36th Tritium Focus Group Meeting Los Alamos National Laboratory, Albuquerque, NM, November 3-5, 2015
Analytical Issue and Solution in H2/D2 R&D
2
• 99+% D2 (product) and H2 (raffinate) from TCAP, better purity than detection limit
• Raffinate has much less D2 than ultra high purity gas cylinder (natural abundance D/H ratio is 155.78 ppm).
• Raffinate impurity correlates with H2 stack emission in tritium operation
• ~ 200 sl TCAP raffinate gas was collected in a hydride bed • The hydride bed was transferred to another room • The raffinate in hydride bed was oxidized into water in a catalyst
evaluation lab reactor • D/H ratio was analyzed by spectroscopy method
TCAP Working Principle
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Feed
Product
Raffinate
Pd/k
Act
ive
PFR
Previous Analysis Using Thermal Conductivity (TCD)
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H. T. Sessions Jr., “Analytical Method for Measuring Total Protium and Total Deuterium in a Gas Mixture Containing H2, D2, and HD via Gas Chromatography”, presented at Tririum Conference 2007, Rochester, NY
H2 analysis using D2 carrier
D2 analysis using H2 carrier
10 ppm resolution lack of low range calibration standards
Tunable Laser for Water Isotope Analysis
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±22.5 ppb (1σ) at 150 ppm D/H ratio
Pathways Considered to Oxidize Hydrogen into Water, Safely!
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Reaction Est. Avg. ∆T TMax (adiabatic)
20.8°C 1790°C
15.5°C 1890°C
57.8°C 3042°C
67.6°C 2790°C
H2 +
CuO H2O +
Cu550
K
Cu + 1/2
O2
(Air) CuO
550 K
H2 +
1/2 O2
(Air) H2O
550 K
Pt/Al2O3
H2 +
1/2 O2
(Air) H2Oambient
Pt/PSDB
Hydrogen autoignition: 565°C Reactor Design Max Temperature: 538°C
Reduction of Cupric Oxide by Hydrogen
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Robert N. Pgase, H. S. Taylor, “Reduction of Cupric Oxide by Hydrogen”, J. Am. Chem. Soc., 1921, 43 (10), pp 2179
150°C
200°C M
oist
ure
Time
Preparation of Copper Oxide
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Hydride Bed Setup
9
heat tape
insulationTECH Mod Bed
heat tape
V-12 V-13 V-14
Temp Control Over PressOver Temppower
PI-103PT-103
(V-52) to H2recombiner
thermocouple thermocouple
TemperatureRead Out
thermocouple
Catalyst Bed Setup
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Catalyst testing lab reactor
V-51
MFC
Ar
N2
Catalystbed
LN2 Trapwith Dewar
Ice Trap
Vent to hood
Water collect
MFC
V-6
V-8
MFCAir
V-5V-52
H2 (cylinder)
H2 (hydride bed)
Typical Tube Reactor Temperature Profile
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Temp, C
69.0 380.0 4
115.0 5164.0 6214.0 7274.0 8344.0 9389.0 10
Set=425 409.0 11419.0 12421.0 13423.0 14
Set=425 423.0 15423.0 16423.0 17422.0 18420.0 19417.0 20
Set=425 411.0 21398.0 22374.0 23343.0 24
bed ave 422.5StDev 0.8Length " 6
7"
25.5"
3
8
13
18
23
50 150 250 350 450
inch
degree C
"Temperature Profile of Catalyst"
6"
Hydrogen Oxidation in Progress
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Hydride bed Lab reactor
Lab reactor temp control
Exothermic Fronts during Hydrogen Oxidation
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Exothermic Fronts during Copper Bed Regeneration
14
Hydride Bed Temperature and Constant Pressure Control
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TCAP Raffinate Purity: 99.998% H2
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H2 + CuO → H2O + Cu Water D/H Ratio, ppm
Test 1 23.2 Test 2 20.3 Test 3 20.5 Test 4 20.1
Single hydride bed supplied gas for 4 tests: • D2 reduction ratio: 25000 (50% in feed to 20 ppm) • Results could be better if residue heel in hydride were purged clean • Oxidation and bed regeneration can combine with co-feed H2 and air
Acknowledgements: Jim Klein for suggesting copper oxide for hydrogen oxidation; Katie Heroux for providing TechMod hydride bed; Greg Staack, Ray Battles, Kurt Breitinger, Sherolyn Bishop, Robert Plonski and Joe Wheeler for reviewing safety documentations; Sharon Redd and Donna Allison for lab supports.