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

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• 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

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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.