热解温度对煤液化残渣可溶有机质热解产物中挥发性组分的影响

Effect of pyrolysis temperature on volatile components in pyrolysis products of soluble organic matter in coal liquefaction residue

为研究热解温度对煤液化残渣可溶有机质热解产物组分的影响,采用超声-索氏相结合萃取法,以甲醇/甲苯混合溶剂作为萃取剂,从神木-府谷次烟煤液化残渣中分离煤液化残渣可溶有机质;借助热裂解气相色谱质谱联用仪,研究了不同温度下(300℃、400℃、450℃、500℃、550℃、600℃和700℃)煤液化残渣可溶有机质的热解产物中挥发性组分的分布特征,探索煤液化残渣可溶有机质直接热解制备高附加值化学品的温度条件。结果表明,煤液化残渣可溶有机质的热解过程包括三个阶段:300℃以下基本不发生热解反应,仅检测到少量挥发性化合物;300℃~600℃为主要的热解阶段,600℃时可检测到的挥发分种类最多,为190种;600℃~700℃的热解反应更剧烈,产物种类趋于集中化,700℃时有机组分全发生缩聚反应,可检测到的挥发分种类为133种。此外,从热解挥发性组分的各族组分的分布规律可以看出,煤液化残渣可溶有机质的热解温度应设置在550℃~600℃;轻馏分油含量随热解温度的升高总体呈减少趋势,重馏分油含量随着温度的升高呈增加趋势。

In order to study the effect of pyrolysis temperature on volatile components in pyrolysis products of soluble organic matter in coal liquefaction residue,the soluble organic matter was separated from Shenmu-Fugu sub-bituminous coal liquefaction residue by ultrasonic-Soxhlet extraction method with methanol/toluene mixed solvent as extraction agent.Furthermore,the distribution characteristics of volatile components in the pyrolysis products of soluble organic matter from coal liquefaction residue at different temperatures(300℃,400℃,450℃,500℃,550℃,600℃and 700℃)were studied by pyrolysis gas chromatography-mass spectrometry.The temperature condition of direct pyrolysis of soluble organic matter from coal liquefaction residue to make high value added chemicals was explored.The results showed that the pyrolysis process of soluble organic matter in coal liquefaction residue had three stages:basically no pyrolysis reaction occurred below 300℃,and only a few volatile compounds were detected;the main pyrolysis stage was from 300℃to 600℃,and 190 volatile types could be detected at 600℃.From 600℃to 700℃,the pyrolysis reaction was more intense and the product types tended to be centralized.At 700℃,the detected volatile types were reduced to 133.In addition,it could be seen from the group distribution of volatile components in pyrolysis that pyrolysis temperature of soluble organic matter in coal liquefaction residue should be set at 550℃-600℃.For light distillate and heavy distillate,the content of light distillate decreased with the increase of pyrolysis temperature,while the content of heavy distillate increased with the increase of pyrolysis temperature.