High temperature measurements for the rate constants of C 1 –C 4 aldehydes with OH in a shock tube
High temperature measurements for the rate constants of C 1 –C 4 aldehydes with OH in a shock tube
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DOI：
10.1016/j.proci.2014.06.112
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Shengkai Wang;D. Davidson;R. Hanson
中科院分区：
文献类型：
--
作者：
Shengkai Wang;D. Davidson;R. Hanson
在 950–1400 K 温度和 1–2 atm 压力下，研究了羟基自由基 (OH) 与一系列醛、甲醛 (CH 2 O)、乙醛 (CH 3 CHO)、丙醛 (C 2 H 5 CHO) 和正丁醛 (nC 3 H 7 CHO) 反应的总速率常数。氢过氧化叔丁基 (TBHP) 快速热分解产生 OH 自由基，通过对 306.69 nm 附近 OH AX (0, 0) 波段中已充分表征的 R 1 (5) 线的窄线宽紫外激光吸收来监测 OH 时程。总体速率常数是通过使用 Veloo 等人 (2013)、USC Mech-II (2007) 和 GRI Mech 3.0 的详细机制将模拟 OH 曲线拟合到测量的 OH 时间历史来推断的。测得的高温醛+ OH速率常数可以用修正的阿伦尼乌斯方程表示，单位为cm 3 mol− 1 s− 1和K，为 k CH 2 O= 1.02× 10 7 T 1.92 exp (779/T)±13% k CH 3 CHO= 4.32× 10 6 T 2.02 exp (716 K/T)±22% k C 2 H 5 CHO= 5.94× 10 6 T 1.98 exp (823 K/T)±27% k nC 3 H 7 CHO= 5.36× 10 6 T 2.06 exp (658 K/T)±25% 在这些测量中没有观察到压力依赖性。测得的甲醛+ OH 反应的速率常数与 Vasudevan 等人 (2005) 之前的实验工作一致，误差在±25% 范围内。对于 C 2–C 4 醛+ OH，本研究首次提供了高温下的直接速率常数测量。通过将当前测量值与文献中现有的低温数据相结合，还确定了覆盖更广泛温度范围（200-1400 K）的更通用的速率常数表达式。这些广泛的表达被认为与大多数现有的实验数据非常一致。
The overall rate constants for the reactions of hydroxyl radicals (OH) with a series of aldehydes, formaldehyde (CH 2 O), acetaldehyde (CH 3 CHO), propionaldehyde (C 2 H 5 CHO) and n-butyraldehyde (nC 3 H 7 CHO), were studied behind reflected shock waves at temperatures of 950–1400 K and pressures of 1–2 atm. OH radicals were produced by rapid thermal decomposition of tert-butyl hydroperoxide (TBHP), and OH time-histories were monitored by narrow-linewidth UV laser absorption of the well-characterized R 1 (5) line in the OH AX (0, 0) band near 306.69 nm. The overall rate constants were inferred by fitting simulated OH profiles to the measured OH time histories using detailed mechanisms of Veloo et al.(2013), USC Mech-II (2007) and GRI Mech 3.0. The measured high-temperature aldehydes+ OH rate constants can be expressed in modified Arrhenius equations, in units of cm 3 mol− 1 s− 1 and K, as k CH 2 O= 1.02× 10 7 T 1.92 exp (779/T)±13% k CH 3 CHO= 4.32× 10 6 T 2.02 exp (716 K/T)±22% k C 2 H 5 CHO= 5.94× 10 6 T 1.98 exp (823 K/T)±27% k nC 3 H 7 CHO= 5.36× 10 6 T 2.06 exp (658 K/T)±25% No pressure dependence was observed in these measurements. The measured rate constant for the formaldehyde+ OH reaction is consistent with previous experimental work from Vasudevan et al.(2005) within±25%. For C 2–C 4 aldehydes+ OH, this study provides the first direct rate constant measurement at high temperatures. More general rate constant expressions covering a much wider temperature range (200–1400 K) were also determined by combining current measurements with existing low temperature data in the literature. These wide-range expressions were seen to be in excellent agreement with most existing experimental data.