Radiation Induced Oxidation of Methanol

Jung, Hak-Jin; Getoff, N.

doi:10.1515/zna-1991-0712

Cited by 5 publications

(3 citation statements)

References 11 publications

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“…It is also of interest to point out that the formation of formaldehyde, glycolic aldehyde, formic and oxalic acids were previously observed in the radiation in duced oxidation of methanol in the presence of air as well as of pure oxygen up to 5 bar [20].…”

Section: Carbonylation Of Aqueous Methanol At Elevated Co-pressurementioning

confidence: 86%

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Radiation Induced Incorporation of CO in Pure and Aqueous Methanol

Jung

Getoff

Lorbeer

1994

Zeitschrift Für Naturforschung A

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Pure and aqueous m ethanol were used for radiation induced incorporation of CO at elevated pressure (up to 15 bar). The initial yields (G,) of the main products in pure methanol under 15 bar CO and 1 bar N 20 were found to be: G, (formaldehyde) = 3.80 and G;(glycolic aldehyde) = 2.0. For aqueous (10" 2 mol • d m -3 ) methanol under 15 bar CO (dose: 0.557 kGy, pH -2): the yields were G (formaldehyde) = 5.44, G (glycolic aldehyde) = 4.0 and G (oxalic acid) = 7.7. At pH = 7 the yields were essentially lower, namely: G(formaldehyde) = 3.2, G(glycolic aldehyde) = 2.0, G(formate) = 3.8 and G (oxalate) = 5.0. Probable reaction-mechanisms for the product form ation are discussed.Based on previous carbonylation experiences of gamma-, electron-and UV-irradiated aqueous m etha nol under 1 bar CO (10" 3 mol • d m -3 CO) [1-6] the aim of the present work was to investigate this process at elevated CO pressures. Pure methanol as well as aqueous solutions were used for this purpose. Experimental R a diation S ource an d S o lu tio n P reparationA "Gammacell 220" (Atomic Energy of C anada Ltd.) was used as a 60Co-y-source, having a dose rate of 40 Gy • min " 1 *. The dosimetry was performed by means of a ferrous-copper dosimeter under the same experimental conditions [7].The applied methanol (p. A. Merck) was freshly distilled under argon atmosphere and kept in absence of air before use. High purity CO (Messer-Griesheim GmbH, Vienna) was used without further purification. The samples (50 ml) of pure or aqueous m ethanol were given into an open glass vessel which was fitted in an autoclave (see Figure 1). Prior to irradiation the solutions were deoxygenated by bubbling for 45 min with high purity argon and then saturated with CO at various pressures (1 -1 5 bar). A n a ly sisAliquots of the irradiated solutions were analyzed by spectrophotom etric methods for the yields of formaldehyde [8], glycolic aldehyde [9], glyoxal [10] and oxalic acid [11]. The total yield of the formed carboxylic acids was determined by titration with 10~3 mol • d m -3 N aO H . The individual measure ment of the formic acid was achieved by water steam distillation of an aliquot of the solution, followed by reduction with magnesia to formaldehyde in acid solution. By substrating the yield of the priorly mea sured aldehydes from the obtained total aldehyde am ount, the formic acid yield was determined. In ad dition to this, the G C-m ethod was applied in most cases, as well for the individual determ ination of gly col and other products. A GC-instrum ent (Carlo Erba 4160) equipped with split/splitless injector, FID and a 20 m glass capillary column with i.d. 0.32 mm coated with CW 20 M (high polymer carbowax, film thick ness 0.2 |im) was used. Hydrogen was applied as car rier gas (flow rate 2.6 ml/min). The injector tempera ture was 260 °C and that of the column 108 °C. The presented yields are mean values of the data obtained 0932-0784 / 94 / 0400-0617 $ 01.30/0. -Please order a reprint rather than making your own copy.

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Section: Carbonylation Of Aqueous Methanol At Elevated Co-pressurementioning

confidence: 86%

“…The radiolysis of water is well understood and can be represented by the brutto reaction (20), where the G-values of the primary species at pH = 7 are given in brackets [16]: In acid solution (pH = 2) eaq is converted into H-atom:…”

Section: Re Ac Don Mechanisms Of the Co-incorporation In Aqueous Methmentioning

confidence: 99%

Radiation Induced Incorporation of CO in Pure and Aqueous Methanol

Jung

Getoff

Lorbeer

1994

Zeitschrift Für Naturforschung A

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“…For the reaction of methanol with dissolved oxygen, organic compounds such as formic acid, aldehyde and carbon dioxide might form. 28,29) However, no organic acid was detected by ion chromatography. The concentration of carbon dioxide was calculated from measured electrical conductivity.…”

Section: Experimental Conditionsmentioning

confidence: 97%

Hydrazine and Hydrogen Co-injection to Mitigate Stress Corrosion Cracking of Structural Materials in Boiling Water Reactors, (II)

Ishida

Wada

Tachibana

et al. 2006

Journal of Nuclear Science and Technology

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Hydrogen and hydrazine co-injection into a boiling water reactor was considered as a new mitigation method of stress corrosion cracking. To confirm decrease of electrochemical corrosion potential by the reduction of oxygen and hydrogen peroxide in bulk water using reducing agent, reaction of hydrazine with oxygen or hydrogen peroxide under simulated downcomer conditions (temperature: 280 C, duration: 4.2 s and gamma-irradiation) was examined. All the oxygen was consumed above the equivalent concentration for the reaction with oxygen within this short time (gammairradiation case) and almost all the hydrogen peroxide was consumed. Reaction rates were accelerated more than five times by gamma-irradiation in each case. Reaction rates with oxygen were compared with other reducing agents such as hydrogen, methanol and ammonia. From the viewpoint of reaction rate and formation of by-product, hydrazine was the most suitable agent. Using a simple model based on the experimental results, water chemistry for the bottom region was calculated for the case of no hydrogen injection and for the case of 0.2 mmolÁkg À1 hydrogen injection into feed water. For both cases, concentrations of dissolved oxygen and hydrogen peroxide were estimated to decrease enough to mitigate SCC, with concentration of ammonia suppressed below the management criteria for reactor water chemistry.

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Radiolytic reduction of merocyanine 540 in methanol solution

Mayer

Krasiukianis

1995

Journal of Radioanalytical and Nuclear Chemistry, Articles

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Radiation Induced Oxidation of Methanol

Cited by 5 publications

References 11 publications

Radiation Induced Incorporation of CO in Pure and Aqueous Methanol

Radiation Induced Incorporation of CO in Pure and Aqueous Methanol

Hydrazine and Hydrogen Co-injection to Mitigate Stress Corrosion Cracking of Structural Materials in Boiling Water Reactors, (II)

Radiolytic reduction of merocyanine 540 in methanol solution

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