Propane pyrolysis facilitated by phenyl radicals: A combined experimental and kinetic modeling study
Propane pyrolysis facilitated by phenyl radicals: A combined experimental and kinetic modeling study
复制标题
DOI：
10.1016/j.ces.2019.115243
复制
发表时间：
2019-12
影响因子：
4.7
通讯作者：
Peng Yu;H. Wong
中科院分区：
文献类型：
--
作者：
Peng Yu;H. Wong
为了加速丙烷裂解制丙烯，引入了由硝基苯生成的苯基作为吸氢剂。在5 5 0~6 5 0 °C范围内进行了纯丙烷裂解和苯基促进的丙烷热解。实验结果表明，苯基促进的丙烷裂解在纯反应条件下具有较高的丙烷转化率，各主要产物的产率均有所提高。但苯基催化裂解的丙烯选择性降低，有利于甲烷和乙烯的生成。详细的动力学模拟结果表明，由于苯基对丙烷的吸氢作用增强，正丙基和异丙基的生成速度加快。苯促热解过程中丙烯选择性的降低是由于丙烯二次反应生成乙烯和甲烷的速率增加所致。我们的工作表明，适当的自由基可以促进丙烷的裂解，从而获得更高的丙烯产率。然而，丙烯产量和选择性之间的平衡仍然是一个重大挑战。
Phenyl radicals generated from nitrobenzene were introduced as hydrogen abstraction agents to accelerate propylene formation from propane pyrolysis. Neat propane pyrolysis and propane pyrolysis facilitated by phenyl radicals were carried out between 550 °C and 650 °C. Our experiments showed that phenyl facilitated pyrolysis gave higher propane conversion over neat reactions, with yields of all main products increased. However, propylene selectivity in phenyl facilitated pyrolysis decreased in favor of methane and ethylene. Results from detailed kinetic modeling showed that the formation of normal propyl and isopropyl radicals was accelerated due to increased hydrogen abstraction of propane by phenyl radicals. Decreased propylene selectivity in phenyl facilitated pyrolysis was resulted from the increased rates of secondary reactions converting propylene into ethylene and methane. Our work demonstrates that a suitable free radical could facilitate propane pyrolysis for higher propylene yields. However, the balance between propylene yields and selectivity remains a major challenge.