Organic iodine removal from simulated dissolver off-gas systems utilizing silver-exchanged mordenite
The removal of methyl iodide by adsorption onto silver mordenite was studied using a simulated off-gas from the fuel dissolution step of a nuclear fuel reprocessing plant. The adsorption of methyl iodide on silver mordenite was examined for the effect of NO/sub x/, humidity, iodine concentration, filter temperature, silver loadings and filter pretreatment. The highest iodine loading achieved in these tests was 142 mg CH/sub 3/I per g of substrate on fully exchanged zeolite, approximately the same as elemental iodine loadings. A filter using fully exchanged silver mordenite operating at 200/sup 0/C obtained higher iodine loadings than a similar filter operating at 150/sup 0/C. Pretreatment of the sorbent bed with hydrogen rather than dry air, at a temperature of 200/sup 0/C, also improved the loading. Variations in the methyl iodide concentration had minimal effects on the overall loading. Filters exposed to moist air streams attained higher loadings than those in contact with dry air. Partially exchanged silver mordenite achieved higher silver utilizations than the fully exchanged material. The partially exchanged mordenite also achieved higher loadings at 200/sup 0/C than at 250/sup 0/C. The iodine loaded onto these beds was not stripped at 500/sup 0/C by either 4.5% hydrogen or 100% hydrogen; however, the iodine could be removed by air at 500/sup 0/C, and the bed could be reloaded. A study of the regeneration characteristics of fully exchanged silver mordenite indicates limited adsorbent capacity after complete removal of the iodine with 4.5% hydrogen in the regeneration gas stream at 500/sup 0/C. The loss of adsorbent capacity is much higher for silver mordenite regenerated in a stainless steel filter housing than in a glass filter housing.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5601265
- Report Number(s):
- CONF-811108-14; ON: DE82004059; TRN: 82-006990
- Resource Relation:
- Conference: Annual meeting of the Institute of Chemical Engineers, New Orleans, LA, USA, 8 Nov 1981
- Country of Publication:
- United States
- Language:
- English
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Organic iodine removal from simulated dissolver off-gas streams using silver-exchanged mordenite
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
FUEL REPROCESSING PLANTS
OFF-GAS SYSTEMS
METHYL IODIDE
REMOVAL
RADIOACTIVE WASTE PROCESSING
ADSORBENTS
ADSORPTION
HUMIDITY
HYDROGEN
ION EXCHANGE MATERIALS
NITROGEN OXIDES
REGENERATION
SILVER COMPOUNDS
TEMPERATURE DEPENDENCE
TRAPS
CHALCOGENIDES
ELEMENTS
HALOGENATED ALIPHATIC HYDROCARBONS
IODINATED ALIPHATIC HYDROCARBONS
MANAGEMENT
MATERIALS
NITROGEN COMPOUNDS
NONMETALS
NUCLEAR FACILITIES
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROCESSING
SORPTION
TRANSITION ELEMENT COMPOUNDS
WASTE MANAGEMENT
WASTE PROCESSING
052001* - Nuclear Fuels- Waste Processing
050800 - Nuclear Fuels- Spent Fuels Reprocessing