油砂组成结构及热解特性分析

采用傅立叶红外光谱仪(FTIR)对四种油砂微观结构和官能团进行研究，通过FTIR谱图的分峰拟合处理，对油砂主要官能团进行半定量分析。研究表明：油砂由芳香烃、脂肪烃、羟基官能团和含氧官能团等组成，其中芳香烃结构和醇类化合物为主。利用TGA/DSC1型同步热分析仪和傅里叶变换红外光谱仪(TG-FTIR)进行了油砂热解特性实验，考察了升温速率对热解特性的影响，探究了油砂热解过程中挥发分的析出规律与主要气相产物H2O、CO2、CO、CH4、CnHm的释放特性。结果表明：油砂热解过程分为干燥脱气段、低温热解和高温热解3个阶段，其中有机质挥发分的析出主要发生在低温热解段；随着升温速率的提高，油砂热解产物释放更加集中，热解特性趋好。油砂热解过程中先析出游离水，随后发生解聚和脱水反应，主要的烷基侧链不断脱落、环化及含氧官能团逐渐断裂生成各种烷烃类、羧酸类、醇类和醛类等物质，甲氧基(-O-CH3)、亚甲基(-CH2-)和甲基(-CH3)在低温段(＜600℃)断裂振动生成有机气体CnHm和CH4。

Experiment to Composition Structure and Pyrolysis Characteristics of Oil Sand

The microstructure and functional groups of four kinds of oil sands were studied by Fourier transform infrared spectroscopy (FTIR). The main functional groups of oil sands were semi-quantitatively analyzed by FTIR spectrum fitting. The results showed that the oil sands are composed of aromatic hydrocarbons, aliphatic hydrocarbons, hydroxyl functional groups and oxygen-containing functional groups, among which aromatic hydrocarbon structure and alcohols are the main components. The pyrolysis characteristics of oil sands were studied by using TGA/DSC1 synchronous thermal analyzer and Fourier transform infrared spectrometer (TG-FTIR). The effects of heating rate on pyrolysis characteristics were studied. And the release characteristics of volatile fractions and the H2O, CO2, CO, CH4 and CnHm were investigated during oil sand pyrolysis. The results showed that the pyrolysis process of oil sands is divided into three stages: dry degassing stage, low temperature and high pyrolysis stage. The volatilization of organic matter mainly occurred in the low temperature zone. With the increase of heating rate, the product release is more concentrated, pyrolysis characteristics tend to be better. During the pyrolysis of oil sands, free water is first precipitated, followed by disaggregation and dehydration. The main alkyl side chains are continuously broken off, the cyclization and oxygen-containing functional groups are gradually broken to form alkanes, carboxylic acids, alcohols and aldehydes and other substances. And methoxy(-O-CH3), methylene (-CH2-) and methyl (-CH3) broken to form organic gases CnHm and CH4 in the low temperature zone.