煤直接液化循环溶剂中饱和烃的分子组成及分布特点

采用全二维气相色谱-飞行时间质谱/氢火焰离子化检测器(GC×GC-TOF MS/FID)从分子水平上对煤直接液化循环溶剂中的饱和烃进行了表征。TOF MS检测器在信噪比(S/N)为200的条件下共检测到599个单体峰,FID检测器在信噪比(S/N)为1000的条件下共检测到458个单体峰。TOF MS的定性结果表明:在GC×GC-TOF MS/FID设定的分析条件下,链烷烃检测到57个单体峰,含有从正戊烷到正三十一烷的完整分布,可达到单体识别;环烷烃共检测到一环烷烃~五环烷烃五种族类,依次检测到104,229,180,28,1个单体峰,可进行每一族类环烷烃中不同碳数的识别。对FID检测器采集的数据进行面积归一化定量,结果表明:链烷烃中主要为正构烷烃,占全部链烷烃的91.86%,一环烷烃中正构烷基环己烷单体的含量比异构烷基环己烷单体的含量大,15种正构烷基环己烷的含量占全部一环烷烃的41.77%;一环烷烃、二环烷烃、三环烷烃、四环烷烃和五环烷烃在煤直接液化循环溶剂中的含量依次为2.11%,14.90%,17.81%,5.30%和0.15%;芳烃组分的总含量为53.64%;含少量含氧杂原子化合物,其含量为0.26%;碳数分布检测结果显示,一环烷烃、二环烷烃、三环烷烃和四环烷烃含量最高的化合物碳数依次为C 13,C 12,C 14和C 16。

Molecular Composition and Distribution Characteristics of Saturated Hydrocarbons in Direct Coal Liquefaction Circulating Solvent

The saturated hydrocarbons in coal direct liquefaction circulating solvents were characterized at the molecular by two-dimensional gas chromatography coupled with time-of-flight MS and FID.The 599 individual peaks were detected by TOF MS detector at a signal-to-noise ratio(S/N)of 200,and 458 individual peaks by FID detector at S/N ratio of 1000.The qualitative results of TOF MS show that in the analysis conditions set by GC×GC-TOF MS/FID,57 monomer peaks are detected in the paraffins,which contains the complete distribution from n-pentane to n-hentriacontane;a total of five groups of naphthenes to pentacycloalkanes are detected which can reach carbon number recognition,and 104,229,180,28,1 monomer peaks are detected in turn.The quantification results of FID show that the paraffins are mainly n-alkanes,accounting for 91.86%of the total paraffins.The content of n-alkylcyclohexane monomers in monocycloalkanes is larger than that of iso-alkylcyclohexane monomers,and the content of 15 kinds of n-alkylcyclohexanes accounts for 41.77%of all monocycloalkanes.The contents of monocycloalkanes,bicycloalkanes,tricycloalkanes,tetracycloalkanes and pentacycloalkanes in the coal direct liquefaction circulating solvent are 2.11%,14.90%,17.81%,5.30%,and 0.15%,respectively;and the component of total aromatic is 53.64%;the content of compounds containing a small amount of oxygen-containing heteroatom is 0.26%.The carbon number distribution test results show that C 13,C 12,C 14,and C 16 are the highest compounds in monocycloalkanes,bicycloalkanes,tricycloalkanes,and tetracycloalkanes.