Experimental and theoretical insight into the soot tendencies of the methylcyclohexene isomers [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 666.3 Pottery
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Energy Efficiency and Renewable Energy ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2018
• Mô tả vật lý: Size: p. 1083-1090 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 264357
• Chủ đề: 1. 09 biomass fuels; 2. Flow reactor; 3. Methylcyclohexene; 4. Particulate matter; 5. Soot

Tóm tắt

The formation of soot precursors during combustion of three positional isomers of methylcyclohexene was investigated in flow reactor experiments and through density functional theory simulations. As evidenced by a recently published structure-property model, the sooting tendencies of these compounds differ from those of structurally similar molecules - suggesting new or unusual reaction chemistry. It was demonstrated that 1-methyl-1-cyclohexene and 4-methyl-1-cyclohexene preferentially react via a retro-Diels-Alder pathway leading to ring opening and molecular weight reduction. 3-methyl-1-cyclohexene, which exhibits much higher yield sooting index, preferentially reacts via dehydrogenation to cyclohexadienes and toluene - consistent with higher soot formation. It was demonstrated that the relative stability of the first radical intermediate plays a considerable role in determining the branching ratio between formation of soot precursors and ring opened retro-Diels-Alder reaction products. This study underscores the importance that small structural features can have in determining the ultimate fate of carbon during combustion processes.