Thermal decomposition of CH3 131I in a gas flow

Kulyukhin, S. A.; Mizina, L. V.; Rumer, I. A.; Konovalova, N. A.

doi:10.1134/s1066362213040115

Cited by 4 publications

(9 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At lower temperatures, the degree of CH 3 131 I decomposition was considerably lower: 13% at 500°C and 83% at 600°С. As we showed in [2], performing the thermal decomposition of CH 3 131 I in the presence of composite materials based on KSKG silica gel containing d elements allows the decomposition temperature to be significantly decreased. Under comparable experimental conditions, the degree of CH 3 131 I decomposition as high as 97-99% is reached at 465 ± 20°С in the presence of a composite material based on KSKG impregnated with compounds of Ni or its mixture with Cu in an amount of 8-10 wt %.…”

mentioning

confidence: 73%

“…I (10 mg) in an air flow in the presence of composite materials KKM-Ni-NH 3 (water vapor-air flow temperature ~23°С, linear velocity of air 4.0-6.0 cm s -1 , water vapor content of the flow ~3-4 vol %, contact time 0.7-0.9 s, Т composite 350 ± 15°С, weight of the composite 10 g, granule size 1.0-3.0 mm, material bed height 4.8 cm, S column ~3.0 cm 2 As we showed in [2], CH 3 131 I is not taken up by the KSKG-based sorbents containing compounds of d elements (Ni, Cu). The main 131 I species localized on these materials is I 2 , which is formed via thermal decomposition of CH 3 131 I.…”

Section: Resultsmentioning

confidence: 99%

“…The experimental procedure and installation used for studying the CH 3 131 I localization from the water vapor-gas flow were the same as in [2]. I (10 mg) in an air flow in the presence of composite materials KKM-Ni-NH 3 (water vapor-air flow temperature ~23°С, linear velocity of air 4.0-6.0 cm s -1 , water vapor content of the flow ~3-4 vol %, contact time 0.7-0.9 s, Т composite 350 ± 15°С, weight of the composite 10 g, granule size 1.0-3.0 mm, material bed height 4.8 cm, S column ~3.0 cm 2 As we showed in [2], CH 3 131 I is not taken up by the KSKG-based sorbents containing compounds of d elements (Ni, Cu).…”

Section: Resultsmentioning

confidence: 99%

“…(1) composites based on KSKG silica gel, prepared by the procedure described in [2]. Ni content 1-10 wt % (designation KKM-Ni-NH 3 );…”

Section: Methodsmentioning

confidence: 99%

“…131 I was used as a tracer for weighable amounts of inactive iodine. Therefore, the designation CH 3 131 I refers to the labeled compound and not to the compound of pure 131 I.All the salts, alkalis, and acids used in the study were of chemically pure grade.The following composite materials based on KSKG silica gel and containing 1-10 wt % Ni were used in the study:(1) composites based on KSKG silica gel, prepared by the procedure described in [2]. Ni content 1-10 wt % (designation KKM-Ni-NH 3 );…”

mentioning

confidence: 99%

See 4 more Smart Citations

Thermal decomposition of CH3 131I in a gas flow in the presence of SiO2-Ni composite material (1–8 wt % Ni)

et al. 2015

Self Cite

View full text Add to dashboard Cite

Thermal decomposition of a volatile organic compound of radioactive iodine, CH 3 131 I, in a gas flow in the presence of various modifications of granulated materials based on KSKG silica gel impregnated with nanometric particles of Ni compounds was studied. The degree of CH 3 131 I decomposition as high as 97-99% is reached at 450 ± 20°С in the presence of granules of KSKG-based composite containing 8 wt % Ni in the form of NiO. The degree of CH 3 131 I decomposition depends on the contact time of the gas phase and composite, temperature of the composite, and amount of CH 3 131 I introduced into the gas flow.Lorenz et al.[1] studied the thermal decomposition of CH 3 131 I and found that the degree of CH 3 131 I decomposition reached 97.9% only at 800°С. At lower temperatures, the degree of CH 3 131 I decomposition was considerably lower: 13% at 500°C and 83% at 600°С. As we showed in [2], performing the thermal decomposition of CH 3 131 I in the presence of composite materials based on KSKG silica gel containing d elements allows the decomposition temperature to be significantly decreased. Under comparable experimental conditions, the degree of CH 3 131 I decomposition as high as 97-99% is reached at 465 ± 20°С in the presence of a composite material based on KSKG impregnated with compounds of Ni or its mixture with Cu in an amount of 8-10 wt %. In all the cases, the composite materials contained 8 wt % Ni. It was interesting to study the catalytic activity of similar materials with lower Ni content.This study was aimed at developing composite materials based on KSKG silica gel and containing 1-6 wt % Ni and at evaluating their ability to catalyze the CH 3 131 I decomposition.In our experiments, we used carrier-free 131 I supplied by OAO Izotop in the form of a Na 131 I solution. EXPERIMENTALThe radioactivity of the nuclide was measured by γ-ray spectrometry with a semiconductor Ge-Li detector on a multichannel analyzer. 131 I was used as a tracer for weighable amounts of inactive iodine. Therefore, the designation CH 3 131 I refers to the labeled compound and not to the compound of pure 131 I.All the salts, alkalis, and acids used in the study were of chemically pure grade.The following composite materials based on KSKG silica gel and containing 1-10 wt % Ni were used in the study:(1) composites based on KSKG silica gel, prepared by the procedure described in [2]. Ni content 1-10 wt % (designation KKM-Ni-NH 3 );(2) composites based on KSKG silica gel impregnated with Ni by treatment of the silica gel with a solution of Ni 2+ chloride, followed by drying at 110°С and conditioning in air at 300°С for 4 h. Ni content 8 wt % (designation KKM-Ni-Cl);(3) composites based on KSKG silica gel, prepared similarly using Ni 2+ sulfate instead of chloride. Ni content 8 wt % (designation KKM-Ni-SO 4 );(4) composites based on KSKG silica gel, prepared similarly using Ni 2+ nitrate instead of chloride.

show abstract

mentioning

confidence: 73%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…(1) composites based on KSKG silica gel, prepared by the procedure described in [2]. Ni content 1-10 wt % (designation KKM-Ni-NH 3 );…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Thermal decomposition of CH3 131I in a gas flow in the presence of SiO2-Ni composite material (1–8 wt % Ni)

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

Effects of moisture and aging upon decomposition of methyl iodide by reduced silver mordenite

Goettsche,

Raja,

Sabbarwall

et al. 2024

Adsorption

View full text Add to dashboard Cite

Reduced silver mordenite has been considered as a sorbent for the capture of organic iodides, especially methyl iodide, from off-gases produced by aqueous used nuclear fuel reprocessing operations. The adsorption capacity of this material has been unpredictable especially when NOx and water are present. Previous work has found that a catalytic decomposition reaction is occurring on the surface but few determinations have been made of the kinetics of this reaction. The work presented tested the adsorption behavior and apparent catalytic reaction rate in humid conditions and compared those to dry conditions testing. Both experiments observed a first order reaction with rate constants of 0.0847 L/g sorbent/s and 0.1202 L/g sorbent/s respectively. Such a reduction in apparent rate constant is possibly due to either water obstructing methyl iodide adsorption or product desorption limitation. Changes in the adsorption profile were also apparent between these two, with the humid conditions experiment reaching saturation sooner than the dry conditions experiment. Additionally, an experiment into the effects of sorbent storage in a controlled laboratory environment was performed. The performance of the sorbent materials that were stored with silver in the zerovalent state was slightly inferior to those materials that were stored in ionic form (Ag+) and reduced to zerovalent silver immediately prior to subjecting them to sorption test. The materials stored with silver in the ionic form (and reduced just prior to application) behaved essentially similarly to the freshly synthesized (and reduced) sorbents in the sorption tests. This suggests that zerovalent silver experiences some oxidation resulting in deactivation of some sites.

show abstract