Understanding the chain mechanism of radical reactions in n-hexane pyrolysis
Understanding the chain mechanism of radical reactions in n-hexane pyrolysis
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DOI：
10.1007/s11164-013-1468-6
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发表时间：
2015-06
影响因子：
3.3
通讯作者：
Da Li;Yingxian Zhao
中科院分区：
文献类型：
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作者：
Da Li;Yingxian Zhao
Pyrolysis ofn-hexane is interpreted in terms of a chain mechanism. The first-order kinetic equation fits experimental data adequately. The rate constant for feed conversion increases from 1.75 × 10−2to 3.79 × 10−1s−1with increasing temperature from 923 to 1,023 K, giving an apparent activation energy of 208.5 ± 1.0 kJ mol−1. Initial primary products consist of hydrogen, C1–C4paraffins, C2–C5olefins,iso-hexanes, and coke. Quantitative interpretation of the chain mechanism shows that different products are formed from different elementary reactions with different selectivity. Increasing temperature promotes homolysis of the feed molecule and β-cracking of radicals and reduces the proportion of H abstraction by radicals, resulting in an increase in production of hydrogen and formation of a more dehydrogenated coke. The average reaction chain length decreases from 7.33 to 5.73 as the temperature is increased from 923 to 1,023 K.
