柴油/甲醇燃烧排放颗粒SOF的组分与形成途径

Components and Formation Pathway of SOF in Diesel/Methanol Combustion Emission Particulates

采用热重分析仪和气相色谱-质谱联用仪，对柴油／甲醇混合燃料（M0、M5、M15）燃烧排放颗粒的可溶有机物（SOF）组分与形成途径进行了分析．热重分析结果表明，随着燃料中甲醇掺混比的增大，燃烧排放颗粒中SOF的质量减少，失重速率峰值升高：气相色谱-质谱联用分析结果表明，3种颗粒SOF中主要由碳数为9～28的正烷烃和支链烷烃组成，还包括一定数量的多环芳香烃类物质和邻苯二甲酸二异辛酯等其他有机物．随着燃料中甲醇掺混比的增加，燃烧排放颗粒SOF中烷烃含量增加，芳香烃含量减少；颗粒中PAHs主要通过脱氢加乙炔反应形成：烷烃类物质主要来自柴油和少量润滑油．

The soluble organic fraction （SOF） of diesel/methanol combustion particulates was analyzed by gas chro- matography/mass spec-trometry（GC/MS ） and thermogravimetry/difference synchronization analyzer. The results showed that the quality of SOF in the combustion particulate and the weight loss rate peak decrease with the increas- ing methanol blending ratio. In the three different particulates, about all of SOF were alkanes with straight orbranch chains, the carbon atoms were from 9 to 28 and a number of polycyclic aromatic hydrocarbons and some other organ- ics such as ethylhexyl phthalate. The alkanes in the particulates increased and the polycyclic aromatic hydrocarbons decreased with the increasing methanol blending ratio. H-abstraction acetylene addition mechanism and self-combina- tion reaction of aromatics were the main routes for polycyclic aromatic formation. The alkanes were mainly be formed by diesel and the lubricating oil.