Primary emissions of glyoxal and methylglyoxal from laboratory measurements of open biomass burning
Primary emissions of glyoxal and methylglyoxal from laboratory measurements of open biomass burning
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DOI：
10.5194/acp-18-15451-2018
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发表时间：
2018-06
影响因子：
6.3
通讯作者：
K. Zarzana;Vanessa Selimovic;A. Koss;K. Sekimoto;M. Coggon;Bin Yuan;W. Dubé;R. Yokelson;C. Warnek
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作者：
K. Zarzana;Vanessa Selimovic;A. Koss;K. Sekimoto;M. Coggon;Bin Yuan;W. Dubé;R. Yokelson;C. Warnek
抽象的。我们报告了在美国国家海洋和大气管理局牵头的2016年FIREX密集活动期间，在密苏拉的火灾科学实验室露天燃烧生物质所产生的乙二醛和甲基乙二醛的排放。这两种化合物都是使用腔增强光谱进行测量的，这种光谱比以前用来测定这两种化合物的排放的方法更灵敏、更有选择性。总共进行了75次燃烧，使用8个不同类别的33种不同燃料，提供了比以前更全面的排放数据集。使用我们的仪器测量甲基乙二醛受到其他几个物种的光谱干扰，这里报告的值可能被低估了，可能高达70%。按摩尔计算，甲基乙二醛的排放量比乙二醛的排放量高2-3倍，而以前的研究报告甲基乙二醛的排放量低于乙二醛的排放量。所有燃料的乙二醛排放比平均为3.6ppbv(Ppmv CO)−1，排放系数平均为0.66±0.50g甲基乙二醛(千克燃料燃烧)−1。生物质燃烧的乙二醛一次排放远低于以前的实验室测量，但与最近飞机上的测量结果一致。所有燃料的乙二醛排放比率平均为1.4ppbv(Ppmv CO)−1，而排放系数平均为0.20±0.12g乙二醛(千克燃料燃烧)−1，这一数值至少比先前全球乙二醛预算估计数低4倍。尽管乙二醛排放比和因素在不同燃料类别之间存在显著差异，但乙二醛和甲醛在任何给定的火灾过程中都高度相关，乙二醛和甲醛的比率在许多不同的燃料类型中是一致的，平均值为0.068±0.018。虽然新鲜排放的RGF值在许多燃料类型中是一致的，但需要进一步的工作来确定该值如何随着排放年龄的变化而变化。
Abstract. We report the emissions of glyoxal and methylglyoxal from the open burning of biomass during the NOAA-led 2016 FIREX intensive at the Fire Sciences Laboratory in Missoula, MT. Both compounds were measured using cavity-enhanced spectroscopy, which is both more sensitive and more selective than methods previously used to determine emissions of these two compounds. A total of 75 burns were conducted, using 33 different fuels in 8 different categories, providing a far more comprehensive dataset for emissions than was previously available. Measurements of methylglyoxal using our instrument suffer from spectral interferences from several other species, and the values reported here are likely underestimates, possibly by as much as 70 %. Methylglyoxal emissions were 2–3 times higher than glyoxal emissions on a molar basis, in contrast to previous studies that report methylglyoxal emissions lower than glyoxal emissions. Methylglyoxal emission ratios for all fuels averaged 3.6±2.4 ppbv methylglyoxal (ppmv CO)−1, while emission factors averaged 0.66±0.50 g methylglyoxal (kg fuel burned)−1. Primary emissions of glyoxal from biomass burning were much lower than previous laboratory measurements but consistent with recent measurements from aircraft. Glyoxal emission ratios for all fuels averaged 1.4±0.7 ppbv glyoxal (ppmv CO)−1, while emission factors averaged 0.20±0.12 g glyoxal (kg fuel burned)−1, values that are at least a factor of 4 lower than assumed in previous estimates of the global glyoxal budget. While there was significant variability in the glyoxal emission ratios and factors between the different fuel groups, glyoxal and formaldehyde were highly correlated during the course of any given fire, and the ratio of glyoxal to formaldehyde, RGF, was consistent across many different fuel types, with an average value of 0.068±0.018. While RGF values for fresh emissions were consistent across many fuel types, further work is required to determine how this value changes as the emissions age.