Isomer-specific speciation behaviors probed from premixed flames fueled by acetone and propanal
Isomer-specific speciation behaviors probed from premixed flames fueled by acetone and propanal
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从丙酮和丙醛燃料的预混合火焰中探测异构体特异性形态行为
DOI：
10.1016/j.proci.2020.06.221
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发表时间：
2020
影响因子：
3.4
通讯作者：
Bin Yang
中科院分区：
文献类型：
--
作者：
H;ong Liao;Tao Tao;Wenyu Sun;Nils Hansen;Bin Yang
本文对两种C 3 羰基异构体丙酮和丙醛分别以不同当量比（1.0和1.5）为燃料的低压预混火焰的化学结构进行了实验研究。通过采用分子束质谱法和可调谐同步加速器光电离获得详细的形态信息。开发了包括丙酮和丙醛化学性质的详细动力学模型，并使用当前的火焰形态测量进行了测试。通过结合实验观察和建模解释，对燃料特定反应途径和由此产生的不同物种库进行了比较。这项工作检测并量化了一些燃料特定的中间体，例如丙酮火焰中的乙烯酮和丙醛火焰中的甲基乙烯酮。特别是，当前模型令人满意地预测了乙烯酮（丙酮的重要初级中间体）的定量形态测量，其中包括更新的乙烯酮子机制。这项工作的主要努力致力于深入了解燃料分子中的羰基位置对预混合火焰条件下形态行为的影响。两种C 3 羰基化合物中的羰基官能团紧密键合，最好保留在CO中。由于两种异构体中C=O键的位置不同，丙醛的氧化导致大量的乙基作为链载体，而丙酮的消耗很容易产生大量的甲基，从而抑制燃料反应性。结果，观察到丙醛的较高反应性。更重要的是，不同的燃料消耗模式也会影响物种形成行为。具体来说，在丙醛火焰中观察到较高浓度的苯前体，例如烯丙基。此外，典型的含氧排放甲醛和乙醛分别在丙酮和丙醛火焰中具有更显着的浓度。
Chemical structures of low-pressure premixed flames respectively fueled by two C 3 carbonyl isomers, ace-tone and propanal, at different equivalence ratios (1.0 and 1.5) were experimentally investigated in this work. Detailed speciation information was obtained by employing molecular-beam mass spectrometry with tunable synchrotron photoionization. A detailed kinetic model including the chemistry of acetone and propanal was developed and tested with the current flame speciation measurements. By combining experimental observa- tions and modeling interpretations, comparisons were made regarding fuel-specific reaction pathways and the resulting different species pools. Some fuel-specific intermediates were detected and quantified in this work, such as ketene in acetone flames and methylketene in propanal flames. Particularly, the quantitative speci-ation measurements of ketene, an important primary intermediate of acetone, were satisfactorily predicted by the current model, which included an updated ketene sub-mechanism. Major efforts in this work were devoted to gaining some insights into the effects of the carbonyl position in fuel molecules on the speciation behaviors under premixed flame conditions. Carbonyl functionalities in the two C 3 carbonyl compounds are tightly bonded and preferably preserved in CO. Due to the different position of the C = O bond in the two isomers, the oxidation of propanal leads to abundant ethyl as a chain carrier, while the acetone consump-tion easily results in a significant amount of methyl, an inhibitor on the fuel reactivity. As a result, higher reactivity of propanal was observed. More importantly, the different fuel consumption patterns also influ-ence the speciation behaviors. Specifically, the larger concentration of benzene precursors such as allyl, was observed in the propanal flames. Besides, typical oxygenated emissions formaldehyde and acetaldehyde had more remarkable concentrations in acetone and propanal flames, respectively.