Do primary nitrosamines form and exist in the gas phase? A computational study of CH3NHNO and (CH3)2NNO

Tang, Yizhen; Hanrath, Michael; Nielsen, Claus J.

doi:10.1039/c2cp42219k

Cited by 22 publications

(34 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Assuming that nitrosamine isomerises as soon as it is formed leading to an imine; 23,25,30 for emission at 10:00 under clear sky conditions, the obtained concentration of R 2 N-NO 2 is practically the same as [R 2 N-NO 2 ] obtained considering that nitrosamine does not isomerise but photolyses to generate back R 2 N radical. Note that, assuming nitrosamine formation, the rate of nitramine formation is 10 times higher than the rate of nitrosamine formation.…”

Section: 2supporting

confidence: 60%

“…23 23,25 The theoretical calculations of Tang et al conclude that primary nitrosamines, RCH 2 NH-NO, are not stable and rapidly form imines by isomerization to RCHNHNOH followed by reaction with O 2 . 30 However, based on the theoretical study of da Silva, RNH-NO are significant products in RNH + NO reactions. 31 The branching ratio for the abstraction at the N-H site, r 1b , was reported to be o0.10 by Nielsen et al, 25 0.15 by Karl et al 23 and 0.17 by Xie et al 26 The SAR calculations lead to r 1b = 0.47.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Branching ratios for the reactions of OH with ethanol amines used in carbon capture and the potential impact on carcinogen formation in the emission plume from a carbon capture plant

Onel

Blitz

Breen

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The OH initiated gas-phase chemistry of several amines that are potential candidates for use in post-combustion carbon capture (PCCC) plants have been studied by laser flash photolysis with OH monitored by laser induced fluorescence. The rate coefficients for the reaction of OH with N-methylethanolamine (MMEA) and N,N-dimethylethanolamine (DMEA) have been measured as a function of temperature (∼300-500 K): k(OH+MMEA) = (8.51 ± 0.65) × 10(-11)(T/298)(-(0.79±0.22), k(OH+DMEA) = (6.85 ± 0.25) × 10(-11)(T/298)(-(0.44±0.12). The results for DMEA lie between previous values. This is the first kinetic study of the OH + MMEA reaction. At low pressures in the presence of oxygen, OH is recycled in the DMEA reaction as has been observed for other tertiary amines. Branching ratios for OH abstraction with MEA, DMEA and MMEA are dominated by abstraction from the αCH2 group. Abstraction from N-H is determined to be 0.38 ± 0.06 for MEA and 0.52 ± 0.06 for MMEA at 298 K. The impact of these studies has been assessed by using a modified chemical box model to calculate downwind concentrations of nitramines and nitrosamine formed in the photo-oxidation of MEA. Under clear sky conditions, the simulations suggest that current safe guidelines for nitramines may be significantly exceeded with predicted MEA emission rates.

show abstract

Section: 2supporting

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Branching ratios for the reactions of OH with ethanol amines used in carbon capture and the potential impact on carcinogen formation in the emission plume from a carbon capture plant

Onel

Blitz

Breen

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Primary nitrosamines do, however, isomerize and react with O 2 within seconds to give the corresponding imines. 50 The initial amine reaction with ozone and OH-Cl-NO 3 radicals constitutes the rate-limiting step in the formation of nitrosamines, nitramines and imines; k 1 is the rate coefficient for oxidant + amine reaction, and k 1a /k 1 is the fraction of the initial oxidation leading to the amino radical. The nitramine yield depends on k 1a /k 1 and the branching in the amino radical reactions with NO, NO 2 and O 2 .…”

Section: Nitrosamine and Nitramine Formationmentioning

confidence: 99%

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

2012

View full text Add to dashboard Cite

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.

show abstract

“…Instead, the reaction between NO and the N-amino radical leads directly to the imine. Recent quantum chemical calculations provided evidence that nitrosamine from primary amines, despite they could form under atmospheric conditions, is in isomerization equilibrium with RNHNOH + which undergoes rapid H-abstraction by O 2 to give the corresponding imine within seconds (Tang et al, 2012). Imines were postulated to be relevant gas-phase products in the photo-oxidation of amines, however literature reports on imines are scarce .…”

Section: Elsevier_stoten_17722mentioning

confidence: 99%

Modelling atmospheric oxidation of 2-aminoethanol (MEA) emitted from post-combustion capture using WRF–Chem

Karl

Svendby

Walker

et al. 2015

Science of The Total Environment

View full text Add to dashboard Cite

Limiting global warming to less than 2 °C relative to pre-industrial levels would require substantial cuts in anthropogenic emissions of greenhouse gases (IPCC, 2014). Carbon capture and storage (CCS) is an important mitigation technology for reducing anthropogenic carbon dioxide (CO 2 ) emissions from industrial and energy-related point sources. In this process, CO 2 is captured, conditioned, compressed and transported to a storage location for long-term isolation from the atmosphere. Several problems can occur during CCS with impacts on the environment. Post-combustion capture from power plants entails emissions of pollutants, solvents and its degradation by-products to the atmosphere, emissions to water and generation of solid waste (e.g. Reynolds et al., 2012). During the further steps of the CCS chain, CO 2 release during transport in pipelines as well as the escape of injected CO 2 from the storage location to the atmosphere or groundwater pose risks to the environment (Koorneef et al., 2012).Modelling atmospheric oxidation of 2-aminoethanol (MEA) emitted from post-combustion capture using WRF--Chem AbstractCarbon capture and storage (CCS) is a technological solution that can reduce the amount of carbon dioxide (CO 2 ) emissions from the use of fossil fuel in power plants and other industries. A leading method today is amine based post-combustion capture, in which 2-aminoethanol (MEA) is one of the most studied absorption solvents. In this process, amines are released to the atmosphere through evaporation and entrainment from the CO 2 absorber column. Modelling is a key instrument for simulating the atmospheric dispersion and chemical transformation of MEA, and for projections of ground-level air concentrations and deposition rates. In this study, the Weather Research and Forecasting model inline coupled with chemistry, WRF--Chem, was applied to quantify the impact of using a comprehensive MEA photo-oxidation sequence compared to using a simplified MEA scheme. Main discrepancies were found for iminoethanol (roughly doubled in the detailed scheme) and 2-nitro aminoethanol, short MEA-nitramine (reduced by factor of two in the detailed scheme). The study indicates that MEA emissions from a full-scale capture plant can modify regional background levels of isocyanic acid. Predicted atmospheric concentrations of isocyanic acid were however below the limit value of 1 ppbv for ambient exposure. The dependence of the formation of hazardous compounds in the OH-initiated oxidation of MEA on ambient levels level of nitrogen oxides (NO x ) was studied in a scenario without NO x emissions from a refinery area in the vicinity of the capture plant. Hourly MEAnitramine peak concentrations higher than 40 pg m − 3 did only occur when NO x mixing ratios were above 2 ppbv. Therefore, the spatial variability and temporal variability of levels of OH and NO x need to be taken into account in the health risk assessment. The health risk due to direct emissions of nitrosamines and nitramines from full-scale CO 2 capture should be i...

show abstract

Do primary nitrosamines form and exist in the gas phase? A computational study of CH3NHNO and (CH3)2NNO

Cited by 22 publications

References 26 publications

Branching ratios for the reactions of OH with ethanol amines used in carbon capture and the potential impact on carcinogen formation in the emission plume from a carbon capture plant

Branching ratios for the reactions of OH with ethanol amines used in carbon capture and the potential impact on carcinogen formation in the emission plume from a carbon capture plant

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

Modelling atmospheric oxidation of 2-aminoethanol (MEA) emitted from post-combustion capture using WRF–Chem

Contact Info

Product

Resources

About