Apparatus and method for simultaneous recovery of hydrogen from water and from hydrocarbons
- Los Alamos, NM
Apparatus and method for simultaneous recovery of hydrogen from water and from hydrocarbon feed material. The feed material is caused to flow over a heated catalyst which fosters the water-gas shift reaction (H.sub.2 O+COH.sub.2 +CO.sub.2) and the methane steam reforming reaction (CH.sub.4 +H.sub.2 O3 H.sub.2 +CO). Both of these reactions proceed only to partial completion. However, by use of a Pd/Ag membrane which is exclusively permeable to hydrogen isotopes in the vicinity of the above reactions and by maintaining a vacuum on the permeate side of the membrane, product hydrogen isotopes are removed and the reactions are caused to proceed further toward completion. A two-stage palladium membrane reactor was tested with a feed composition of 28% CQ.sub.4, 35% Q.sub.2 O (where Q=H, D, or T), and 31% Ar in 31 hours of continuous operation during which 4.5 g of tritium were processed. Decontamination factors were found to increase with decreasing inlet rate. The first stage was observed to have a decontamination factor of approximately 200, while the second stage had a decontamination factor of 2.9.times.10.sup.6. The overall decontamination factor was 5.8.times.10.sup.8. When a Pt/.alpha.-Al.sub.2 O.sub.3 catalyst is employed, decoking could be performed without catalyst degradation. However, by adjusting the carbon to oxygen ratio of the feed material with the addition of oxygen, coking could be altogether avoided.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- Assignee:
- Regents of University of California (Los Alamos, NM)
- Patent Number(s):
- US 6165438
- OSTI ID:
- 873463
- Country of Publication:
- United States
- Language:
- English
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method
simultaneous
recovery
hydrogen
water
hydrocarbons
hydrocarbon
feed
material
caused
flow
heated
catalyst
fosters
water-gas
shift
reaction
coh
methane
steam
reforming
o3
reactions
proceed
partial
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pd
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exclusively
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isotopes
vicinity
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cq
35
31
hours
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tritium
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rate
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approximately
200
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-al
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decoking
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adjusting
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oxygen
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addition
coking
altogether
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simultaneous recovery
decontamination factor
hydrogen isotope
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feed material
steam reforming
hydrogen isotopes
shift reaction
reforming reaction
oxygen ratio
hydrocarbon feed
gas shift
overall decontamination
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