Heterogeneous cracking of catechol under partially oxidative conditions
Heterogeneous cracking of catechol under partially oxidative conditions
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DOI：
10.1016/j.fuel.2003.11.016
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发表时间：
2004-08
期刊：
影响因子：
7.4
通讯作者：
E. Shin;M. Hajaligol;F. Rasouli
中科院分区：
文献类型：
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作者：
E. Shin;M. Hajaligol;F. Rasouli
在350-650 °C的温度范围内和在部分氧化条件下，使用纳米颗粒氧化铁研究了邻苯二酚的非均相裂解。我们采用了流管反应器设置为非均相裂解，分子束质谱仪的裂解产物的真实的时间采样和测量，因子分析，以解卷积复杂的化学。考虑了邻苯二酚进料速率、氧气浓度和温度等工艺参数对转化率和产物分布的影响。邻苯二酚的热分解开始于500 °C以上。然而，在氧化铁的存在下，儿茶酚在低至350 °C的温度下显著分解。在较低的邻苯二酚进料速率下促进二氧化碳和水的形成。较高的邻苯二酚进料速率抑制了转化率，并增强了单环芳族产物的形成，特别是通过气相二次反应形成芳族酮茚满酮（m/z 132，C9 H8 O）。然而，将氧浓度增加至21%完成了邻苯二酚的裂解，即使在350 °C下对于高邻苯二酚进料速率也增加了二氧化碳和水的形成。氧化铁在较低温度（350至400 °C）下暴露于邻苯二酚蒸气后失活。然而，它在450 °C以上的温度下仍保持其活性。高分辨率透射电子显微镜被用来表征在各种反应条件下的氧化铁纳米粒子。
Heterogeneous cracking of catechol over the temperature range of 350–650 °C and under partially oxidative conditions was studied using nano-particle iron oxide. We employed a flow tube reactor set-up for heterogeneous cracking, a molecular beam mass spectrometer for the real time sampling and measurement of cracking products, and factor analysis to deconvolute the complex chemistry. The effects on conversion and products distribution of varying process parameters such as catechol feed rate, oxygen concentration, and temperature were considered. Thermal decomposition of catechol begins at above 500 °C. In the presence of the iron oxide, however, catechol significantly decomposes at temperatures as low as 350 °C. The formation of carbon dioxide and water was promoted at the lower catechol feed rates. Higher catechol feed rates suppressed the conversion and enhanced the formation of single ring aromatic products, especially the formation of an aromatic ketone, indanone (m/z 132, C9H8O), through gas-phase secondary reactions. Increasing oxygen concentration up to 21%, however, completed the cracking of catechol with increasing formation of carbon dioxide and water even at 350 °C for a high catechol feed rate. The iron oxide was deactivated after being exposed to the vapor of catechol at lower temperatures (between 350 and 400 °C). However, it retained its activity at temperatures above 450 °C. High-resolution transmission electron microscopy was used to characterize the iron oxide nano-particles at various reaction conditions.