Researches On The Pyrolysis Of Methyl Nitrite And Nitromethane

In this thesis,the pyrolysis of methyl nitrite and nitromethane has been researched with experimental and kinetic model.In the experiments,the methyl nitrite has been synthesized firstly.The concentration of nitrogen oxides of methyl nitrite pyrolysis has been detected online by the flue gas analyzer.Besides,the emission spectra of excited formaldehyde that produced from the pyrolysis of methyl nitrite has been collected by the ICCD detector.In the theoretical work,the kinetic model for the pyrolysis of methyl nitrite is developed which including 24 species and 126 reactions.The mole fraction profiles of the species produced by the pyrolysis of methyl nitrite are researched.By sensitivity analysis,the reaction pathway diagrams of methyl nitrite pyrolysis have been revealed.The results show that the temperature range of methyl nitrite pyrolysis is 500?800 K under 0.98 atm.The pyrolysis of methyl nitrite is mainly through the O-N bond fission,forming hydrocarbons and nitrogen oxides.Then the hydrocarbons are oxidized while the nitrogen oxides enhancing this process is reduced.In the process,nitrogen oxides are converted into nitric oxide as the final product.And the hydrocarbons are converted into products such as carbon monoxide,hydrogen,methane and carbon dioxide etc.In the meantime,the intermediate products such as formaldehyde and methanol are also produced.In order to contrast with methyl nitrite,the pyrolysis of nitromethane is studied as its isomers under the same conditions.The kinetic model of nitromethane pyrolysis is developed,which including 24 species and 119 reactions.And the mole fraction profiles of the species produced by the pyrolysis of nitromethane are researched.By sensitivity analysis,the pyrolysis of nitromethane is mainly through the C-N bond fission,which is different with methyl nitrite.The temperature range of nitromethane pyrolysis is 7801000 K,which is higher than methyl nitrite.The results show that products of nitromethane pyrolysis are nitric oxide,carbon monoxide,methane,water and carbon dioxide.These observations has reflected their similarities and differences in fuel structures,which can help to further understand the chemistry in the pyrolysis of other alkyl nitrite.