预热处理对褐煤热解过程氧元素迁移的影响

以中国呼伦贝尔褐煤为原料，基于工业分析、元素分析、傅里叶变换红外光谱、气相色谱-质谱联用分析，考察140-230℃预热处理对褐煤650℃等温热解氧迁移的影响。结果表明，与未经预热处理的干煤热解相比，褐煤经200℃预热处理后热解，迁移至热解水和半焦中的氧分别下降7.55%和1.43%，迁移至焦油和气体中的氧分别增加6.66%和1.61%，焦油中酚类氧增加一倍。褐煤预热过程中氢键的减少与热解焦油中正己烷可溶物所含酚类化合物的增加，经原位红外漫反射光谱分析，发现源自OH…π、OH…N和羟基自缔合氢键在预热过程中断裂形成自由OH·，导致酚类化合物中苯酚和甲酚含量增加。

Effect of preheating treatment on oxygen migration during lignite pyrolysis

The effect of preheating treatment (140–230°C) on the oxygen migration rule of Hulunbuir lignite which is pyrolyzed at 650°C has been discussed by using the proximate and ultimate analyses, the Fourier transform-infrared spectroscopy, and the gas chromatography-mass spectrometry analysis. Results show that the amount of oxygen migrated to the pyrolysis water and semi-coke is decreased by 7.55% and 1.43%, respectively due to the effect of preheating at 200°C. Furthermore, the amount of oxygen transferred to tar and gas is increased by 6.66% and 1.61% respectively, and phenolic oxygen in tar is getting doubled. The decrease of hydrogen bonding and the increase of phenolic compounds are noted as the result of preheating process of lignite, as evidenced by in-situ infrared diffuse reflectance spectroscopy, this could be due to the dissociation of OH···π, OH···N bonds. Hydroxyl self-association hydrogen bonds have also broken down and transformed during the preheating process with the formation of free OH·, which result in the increase of phenol and cresol contents.