关键词: 固相萃取, 费托合成, 中间馏分, 气相色谱-质谱, 气相色谱-飞行时间质谱, 碳数分布

Abstract: SiO₂/Ag-Al₂O₃ double column solid phase extraction was used to separate the middle fraction of Fischer-Tropsch synthetic oil（F-T oil） into saturated hydrocarbons, olefins, aromatics and oxides etc. , and gas chromatography-mass spectrometry/hydrogen flame ionzation detector (GC-MS/FID) and gas chromatography field ionization time of flight mass spectrometry (GC-FI TOF MS) were used to characterize the type and carbon number distribution of each component. The results show that the middle fraction of low temperature F-T oil is mainly composed of n-alkanes, α-olefins and normal alcohols, whose contents are 41.0%, 30.3% and 8.8%, respectively, and other compounds are basically isomeric compounds. The middle fraction of high temperature F-T oil is complex, and the normal compounds are reduced while the proportions of isomeric compounds are significantly increased. Cycloalkanes were found in saturated hydrocarbons, dienes, trienes or cycloalkenes were found in olefins, and monocyclic aromatics were main aromatics.

Key words: solid phase extraction, Fischer-Tropsch synthesis, middle fraction, gas chromatography-mass spectrometry, gas chromatography-time of flight mass spectrometry, carbon number distribution