FUEL 256 |
| Cycloparaffins are an important component of gasoline and diesel fuels. Low temperature oxidation of cyclohexane has been studied in closed reactors and rapid compression machines, which revealed that during low temperature oxidation most six-membered rings are preserved and the reaction proceeds via two major pathways: dehydrogenation to form conjugated cycloalkenes and peroxidation to form cyclohexene epoxide. Oxidation of methylcyclohexane is studied on a motored engine at various compression ratios. Two-stage and single-stage ignition are observed. Analysis of reaction intermediates shows that the cyclohexane ring is preserved at early oxidation stage. The dominant reaction proceeds through dehydrogenation to form conjugated cycloalkenes instead of peroxidation to form cyclohexene epoxides. The first H-abstraction to form methylcyclohexyl radical is most likely to occur at the p- and m- positions relative to the methyl group and least likely on the methyl group. Demethylation via â–scission also occurs but is favored at high temperature. |
|
Chemistry of Solid, Liquid, and Gaseous Fuels
8:15 AM-12:15 PM, Thursday, August 23, 2007 Boston Park Plaza -- Arlington Rm, Oral
Division of Fuel Chemistry |