Detailed Kinetic Modeling of NO x -Mediated Oxidative Dehydrogenation of Propane
Detailed Kinetic Modeling of NO x -Mediated Oxidative Dehydrogenation of Propane
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NO x 介导的丙烷氧化脱氢的详细动力学模型
DOI：
10.1021/acs.iecr.1c02635
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发表时间：
2021
影响因子：
4.2
通讯作者：
Wong, Hsi-Wu
中科院分区：
文献类型：
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作者：
Yu, Peng;Liu, Yilang;Deshlahra, Prashant;Wong, Hsi-Wu
页岩气正在振兴美国的化学工业，并将乙烯生产从石油石脑油转移到页岩衍生的乙烷，导致丙烯供应短缺。NOx（NO和NO2）介导的丙烷氧化脱氢提供了一种潜在的在没有固体催化剂的情况下将丙烷转化为丙烯的途径。在这项工作中，详细的动力学模型进行模拟气相均相NOx介导的丙烷氧化脱氢。与实验结果相一致，我们的模型表明，丙烷转化率增加与在进料中的NO的量，与丙烯和乙烯的选择性降低，随着丙烷转化率的增加。我们的模拟结果还表明，OH自由基是消耗丙烷的主要物种。NOxin的加入增加了OH自由基的产生，这是由于NO-NO2循环中的额外途径，包括（1）NO被HO 2自由基氧化，（2）NO2被H自由基还原，以及（3）HONO及其异构体的形成和解离，从而促进丙烯的形成。H2O的加入通过移动OH猝灭反应的平衡进一步加速丙烷转化。一个反应网络组成的丙烷热解，丙烷氧化脱氢，和NOx的调解勾勒解释实验中观察到的重要趋势。
Shale gas is revitalizing America’s chemical industry and shifting ethylene production from oil-based naphtha to shale-derived ethane, causing a short supply of propylene. Oxidative dehydrogenation of propane mediated by NOx(NO and NO2) provides a potential route to convert propane into propylene without solid catalysts. In this work, detailed kinetic modeling was performed to simulate gas-phase homogeneous NOx-mediated oxidative dehydrogenation of propane. Consistent with the experimental findings, our model suggests that propane conversion increases with the amount of NO in the feed, with the selectivity to propylene and ethylene decreased with increasing propane conversion. Our modeling results also revealed that OH radicals are the major species to consume propane. The addition of NOxin the system increases the production of OH radicals due to additional pathways in the NO–NO2cycle, including (1) oxidation of NO by HO2radicals, (2) reduction of NO2by H radicals, and (3) formation and dissociation of HONO and its isomers, facilitating propylene formation. The addition of H2O further accelerates propane conversion by shifting the equilibrium of OH quenching reactions. A reaction network consisting of propane pyrolysis, propane oxidative dehydrogenation, and NOxmediation was sketched to explain the important trends observed in the experiments.