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.
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DOI：
10.1039/c5cp04083c
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
L. Onel;M. Blitz;Jessica R. Breen;A. Rickard;P. Seakins
中科院分区：
文献类型：
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作者：
L. Onel;M. Blitz;Jessica R. Breen;A. Rickard;P. Seakins
通过激光闪光光解研究了几种胺的 OH 引发的气相化学，这些胺是用于燃烧后碳捕获 (PCCC) 工厂的潜在候选者，并通过激光诱导荧光监测 OH。测量了 OH 与 N-甲基乙醇胺 (MMEA) 和 N,N-二甲基乙醇胺 (DMEA) 反应的速率系数随温度 (∼300-500 K) 的变化： 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)。DMEA 的结果介于之前的值之间。这是 OH + MMEA 反应的第一个动力学研究。在氧气存在的低压下，OH 在 DMEA 反应中循环利用，正如在其他叔胺中观察到的那样。用 MEA、DMEA 和 MMEA 提取 OH 的支化比在 298 K 下，从 αCH2 基团中提取的 N-H 确定为 0.38 ± 0.06，对于 MMEA 为 0.52 ± 0.06。通过使用改进的化学盒模型来计算在晴空条件下 MEA 光氧化中形成的硝胺和亚硝胺的顺风浓度，评估了这些研究的影响。硝胺可能会显着超出预测的 MEA 排放率。
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.