Pyrolysis characteristics of oil shale and analysis of methane evolution mechanism

doi:10.11949/j.issn.0438-1157.20180459

Abstract

Abstract:

Pyrolysis experiments were conducted on a unit of thermogravimetric-infrared (TG-FTIR) spectrometry to examine the evolution characteristics of methane from pyrolysis of oil shale obtained from three locations (LK, NM, and WQ). The Fourier transform infrared (FTIR) spectroscopy was applied to investigate the functional groups of oil shale. The results show that the pyrolysis process of oil shale could be divided into four stages. The pyrolysis reactions and release of volatiles mainly occurred in the second stage (400-600℃). The evolution of methane was closely related to the content of aliphatic hydrocarbons in oil shale (the absorption band of 3000-2800 cm^-1). The higher content of aliphatic hydrocarbons, the more methane generated during pyrolysis process. By the peak fitting and binding kinetics analysis of the methane precipitation curve, it is concluded that the formation of methane is a result of a desorption process and four chemical reactions.

Key words: oil shale, pyrolysis, TG-FTIR, methane, kinetics

摘要：

为研究油页岩热解特性及热解过程中甲烷的释放规律，采用热重-傅里叶变换红外光谱（TG-FTIR）对龙口（LK）、内蒙（NM）、汪清（WQ）三个地区的典型油页岩进行热解实验，并结合固相红外（FTIR）对油页岩的官能团结构进行分析。研究结果表明，油页岩热解过程可分为四个阶段，热解反应及挥发分释放主要发生在第二阶段（400～600℃）。甲烷的析出与油页岩结构中的脂肪烃（光谱范围3000～2800 cm^-1）密切相关，脂肪烃含量越多，热解过程中释放的甲烷越多。通过对甲烷析出曲线分峰拟合及结合动力学分析，得出甲烷的生成是由一个脱吸附过程和四个化学反应共同作用的结果。

关键词: 油页岩, 热解, TG-FTIR, 甲烷, 动力学

CLC Number:

TQ533

WANG Qing, GUAN Jing, XU Fang. Pyrolysis characteristics of oil shale and analysis of methane evolution mechanism[J]. CIESC Journal, 2018, 69(10): 4362-4370.

王擎, 关京, 徐芳. 油页岩热解特性及其甲烷释放规律研究[J]. 化工学报, 2018, 69(10): 4362-4370.

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