Experimental investigation of thermal decomposition of dihydroxybenzene isomers: Catechol, hydroquinone, and resorcinol
Experimental investigation of thermal decomposition of dihydroxybenzene isomers: Catechol, hydroquinone, and resorcinol
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DOI：
10.1016/j.jaap.2016.05.019
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发表时间：
2016-07
影响因子：
6
通讯作者：
Huamei Yang;Yuki Furutani;Shinji Kudo;J. Hayashi;K. Norinaga
中科院分区：
文献类型：
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作者：
Huamei Yang;Yuki Furutani;Shinji Kudo;J. Hayashi;K. Norinaga
在这项研究中，二羟基苯异构体，如邻苯二酚，间苯二酚和对苯二酚被用来作为模型的挥发物从固体燃料，以更好地阐明固体燃料的热化学转化的机制。这些异构体在两级管式反应器中热解，停留时间高达3.6 s，温度范围为650 - 950 °C。在线气相色谱法共鉴定出51种产物。三种异构体的热解产物分布有很大的不同，对苯二酚的热解产物主要是对苯醌，邻苯二酚和间苯二酚的热解产物中分别没有检测到邻苯醌和间苯醌。CO是由邻苯二酚、间苯二酚和对苯二酚形成的主要最终产物，最大产率分别为27.3wt%、19.4wt%和20.0wt%，而在950 °C和0.3s下由间苯二酚产生的CO2（15.5wt%）显著高于由对苯二酚（1.0wt%）和邻苯二酚（0.8wt%）产生的那些。考虑到C1-C5轻烃的质量选择性，分析了邻苯二酚、间苯二酚和对苯二酚热解生成CO和CO2的可能途径。邻苯二酚主要通过氢迁移和开环反应生成CO和C4烃。对苯二酚主要生成CO、C2和C4碳氢化合物，初始步骤是形成对苯醌。在间苯二酚热裂解过程中，CO和CO2的生成与C1-C5烃类的生成以几乎相等的质量选择性发生竞争反应。与邻苯二酚和对苯二酚相比，间苯二酚生成的C5烃量明显增加，说明间苯二酚热解生成大量CO2是由分子内的醛基和酮基结合所致。
In this study, dihydroxybenzene isomers such as catechol, resorcinol, and hydroquinone were used as models of volatiles from solid fuels to better elucidate the mechanism of the thermochemical conversion of solid fuels. These isomers were pyrolyzed in a two-stage tubular reactor with a residence time up to 3.6 s and temperature ranging from 650 to 950 °C. In total, 51 products were identified by online gas chromatography. The product distribution from the pyrolysis of the three isomers was quite different.p-Benzoquinone was the primary product obtained from the pyrolysis of hydroquinone, while o-benzoquinone and m-benzoquinone were not detected from the pyrolysis of catechol and resorcinol, respectively. CO was the major final product formed from catechol, resorcinol, and hydroquinone, with maximum yields of 27.3 wt%, 19.4 wt%, and 20.0 wt%, respectively, whereas CO2(15.5 wt%) generated from resorcinol was significantly higher than those generated from hydroquinone (1.0 wt%) and catechol (0.8 wt%) at 950 °C and 0.3 s. Considering the mass selectivity of C1–C5light hydrocarbons, the possible reaction pathways leading to CO and CO2were analyzed to describe the pyrolysis of catechol, resorcinol, and hydroquinone. Catechol mainly afforded CO and C4hydrocarbons by H-migration and ring-opening reactions. Hydroquinone mainly generated CO, C2, and C4hydrocarbons, with the initial step being the formation ofp-benzoquinone. During the pyrolysis of resorcinol, competition reactions occurred for the formation of CO and CO2with the production of C1–C5hydrocarbons at a nearly equal mass selectivity. Compared with catechol and hydroquinone, resorcinol produced significantly more C5hydrocarbons, which suggested the intramolecular combination of aldehyde radical and ketone radical for explaining the large amount of CO2formed from the pyrolysis of resorcinol.