Factors influencing the rate of formation of nitrosomorpholine from morpholine and nitrite. II. Rate enhancement in frozen solution

Fan, Tsai-Yi; Tannenbaum, Steven R.

doi:10.1021/jf60190a023

Cited by 15 publications

(3 citation statements)

References 7 publications

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“…Several studies on the kinetics of nitrosamine formation have been reported. [109][110][111][112][113] The mechanisms of these reactions and the atmospheric importance of this formation pathway are, however, quite uncertain and even the reaction order is not clear. Keefer and Roller 114 reported that the nitrosation of secondary amines takes place even in neutral and basic media, and that the reaction is catalysed by formaldehyde.…”

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confidence: 99%

Atmospheric chemistry and environmental impact of the use of amines in carbon capture and storage (CCS)

2012

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This critical review addresses the atmospheric gas phase and aqueous phase amine chemistry that is relevant to potential emissions from amine-based carbon capture and storage (CCS). The focus is on amine, nitrosamine and nitramine degradation, and nitrosamine and nitramine formation processes. A comparison between the relative importance of the various atmospheric sinks for amines, nitrosamines and nitramines is presented.

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confidence: 99%

Atmospheric chemistry and environmental impact of the use of amines in carbon capture and storage (CCS)

2012

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“…It is not an uncommon phenomenon that reaction rates in ice are faster than those in solution. − In most cases, the freeze-concentration into unfrozen solution in ice (when each small region of unfrozen solution existing in ice is indicated, we use the term “micro-pocket”) is the main reason for the increase in reaction rate. Pincock reported an acceleration theory for the freeze-concentration effect .…”

Section: Introductionmentioning

confidence: 99%

Acceleration of Ammonium Nitrite Denitrification by Freezing: Determination of Activation Energy from the Temperature of Maximum Reaction Rate

et al. 2011

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A reaction of ammonium nitrite in ice was investigated. Upon freezing, some nitrite is oxidized by dissolved oxygen and some nitrite reacts with ammonium to produce nitrogen and water in a denitrification reaction. The former reaction was accelerated only during freezing, and the latter one was accelerated even after the whole sample was frozen. The denitrification reaction proceeded at very low concentration in ice, which were conditions under which the reaction would not proceed in solution. The nitrogen production increased linearly with increasing initial concentration of ammonium nitrite. The concentration factor in the unfrozen solution in ice was estimated to be 50.6 when the initial concentration was 0.5 mmol dm(-3), as obtained from comparison of reaction rates in solution and in ice. A new method for determination of the activation energy is proposed that gives a value of 53 to 61 kJ mol(-1) for denitrification. The reaction order of the denitrification process is also determined using our method, and it is concluded to follow third-order kinetics.

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“…Rates of chemical reactions in aqueous solution are generally suppressed with decreasing temperature. However, some reactions are accelerated in ice despite being at lower temperatures than in solution. − The acceleration of reactions in ice has been studied actively since the 1960s in the field of food chemistry and biochemistry, where acceleration mechanisms were reported. Pincock reviewed the reactions in frozen systems 1 and concluded that freeze-concentration in an unfrozen solution of ice was the only cause of acceleration in such systems.…”

Section: Introductionmentioning

confidence: 99%

Chemical Kinetics of Reactions in the Unfrozen Solution of Ice

2007

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Some reactions are accelerated in ice compared to aqueous solution at higher temperatures. Accelerated reactions in ice take place mainly due to the freeze-concentration effect of solutes in an unfrozen solution at temperatures higher than the eutectic point of the solution. Pincock was the first to report an acceleration model for reactions in ice,1 which successfully simulated experimental results. We propose here a modified version of the model for reactions in ice. The new model includes the total molar change involved in reactions in ice. Furthermore, we explain why many reactions are not accelerated in ice. The acceleration of reactions can be observed in the cases of (i) second- or higher-order reactions, (ii) low concentrations, and (iii) reactions with a small activation energy. Reactions with a buffer solution or additives in order to adjust ion strength, zero- or first-order reactions, or reactions containing high reactant concentrations are not accelerated by freezing. We conclude that the acceleration of reactions in the unfrozen solution of ice is not an abnormal phenomenon.

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Factors influencing the rate of formation of nitrosomorpholine from morpholine and nitrite. II. Rate enhancement in frozen solution

Cited by 15 publications

References 7 publications

Atmospheric chemistry and environmental impact of the use of amines in carbon capture and storage (CCS)

Atmospheric chemistry and environmental impact of the use of amines in carbon capture and storage (CCS)

Acceleration of Ammonium Nitrite Denitrification by Freezing: Determination of Activation Energy from the Temperature of Maximum Reaction Rate

Chemical Kinetics of Reactions in the Unfrozen Solution of Ice

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