澳大利亚烟煤热解的拉曼光谱研究

Raman spectroscopic study on the pyrolysis of Australian bituminous coal

采用拉曼光谱考察了澳大利亚烟煤在常压、温度为298～1 473K条件下,不同热解气氛（Ar和N2）下的热解性能.结合AD/Aall 、AG/All、WG以及PG-PD等表征参数分析发现,澳大利亚烟煤的热解可以分为三个阶段：298～ 873 K为固有小分子和大分子键能较弱处断裂分解产生的小分子化合物的析出沉积和挥发;873～1 273 K为大分子化合物裂解挥发和炭化;1 273～1 473K为焦炭的石墨化.在N2和Ar气氛经1473 K热处理后,焦炭的不同杂化结构的碳相对含量呈现明显差异.不同保温时间下,其煤焦碳结构演变趋势相似,但保温时间越长,越有利于小分子挥发分在较低温度的挥发.

Raman spectroscopy was applied to investigate the temperature dependent pyrolysis of Australian bituminous coal from 298 to 1 473 K in argon and nitrogen atmospheres. The results indicated that the pyrolysis of Australian bituminous coal can be divided into three stages ： 298 - 873 K, precipitation and volatilization of small molecule compounds （original in coal or decomposed by heat treatment） ; 873 - 1 273 K, cracking and volatilization of macromolecular compounds; 1 273 -1 473 K, graphitization of coke. After annealing at 1 473 K, the ordered carbon content of coke is significantly related to the atmosphere of nitrogen or argon; nitrogen is conducive to the pyrolysis of coal. Annealing or holding time exhibits little effect on coal pyrolysis and coke structure evolution; however, long holding time is helpful for the volatilization of small molecules at low temperature.