Experimental And Kinetic Modeling Studies On Pyrolysis Of C4Alkenes And Alkanes

Experimental (SVUV-PIMS) and kinetic studies have been carried out on the pyrolysis of C4alkenes and alkanes fuels (1-butene,2-butene, iso-butene, n-butane and iso-butane) at high temperature and low pressure in this dissertation.In the first chapter, we introduced the research background, history, aim and significance about the combustion characteristic of C4alkenes and alkanes. Firstly, we stated the necessity and importance of the study for the combustion characteristic of C4alkenes and alkanes, because of the impact and pollutants from fossil fuels combustion. Meanwhile, the importance and the role of the combustion characteristic of C4alkenes and alkanes for utilization of biomass fuels such as alcohols and furan are illustrated. Then, the history and disadvantage of the study about the combustion characteristic of C4alkenes and alkanes are summarized. Finally, the aim and significance of this dissertation are presented..In Chapter2, the experimental setup, experimental methods and calculation method of pyrolysis are introduced. Experimentally, the diagnostic methods, superiority of synchrotron radiation vacuum ultraviolet photoionization, experiment setup of pyrolysis, temperature correction, experimental modes and data processing are summarized. This chapter focus on the measurement and result of the temperature profiles along the centerline of the flow tube as well as the optimization of the time-of-flight mass spectrometer. For the kinetic model, the input parameters for CHEMKIN PRO calculation are illustrated, especially with focusing on the plug flow reactor code.In Chapter3, firstly, the experiment condition and results are illustrated. Two experimental mode are carried out:(1) The mass spectra are recorded at a fixed pyrolysis temperature for various photon energies to yield photoionization efficiency (PIE) spectra. The ionization energies (IEs) obtained with near-threshold PIE measurements are useful for species identification. In this study, about twenty species are measured and identified from1-butene pyrolysis, such as H2, CH3, CH4, C2H2, C2H3, C2H4, C2H5, C2H6, C3H3, pC3H4, aC3H4, aC3H5, C3H6, C4H2, C4H4,1,3-C4H6,2-C4H8,1-C4H8,1,3-C5H6and C6H6.(2) The mass spectra are recorded at fixed photon energies for various pyrolysis temperatures to yield mole fraction profiles of pyrolysis species versus temperatures. Secondly, a detailed kinetic model is developed to simulate the pyrolysis processes. Satisfactory agreement is achieved between the experimental and predicted mole fraction profiles of pyrolysis species. Rates of production analysis (ROP) and sensitivity analysis (SEN) indicates the decomposition reaction sequences in detail.In Chapter4,2-butene pyrolysis is studied by the two experimental modes as mentioned above. A compatible kinetic model with the1-butene pyrolysis is developed to simulate the2-butene pyrolysis processes. The detail pyrolysis process are analyzed and presented according to the ROP analysis and SEN analysis. Meanwhile, the similarities and differences between1-butene and2-butene pyrolysis are compared.In Chapter5, the pyrolysis of i-butene is studied with the same method. To simulate i-butene pyrolysis processes, a compatible kinetic model with the two linear butenes (1-butene and2-butene) pyrolysis is developed. The pyrolysis result is studied and stated by the ROP and SEN analysis. At the same time, the three butene isomers pyrolysis are compared and summarized.n-Butane pyrolysis is carried out by the two experimental modes as that in the three isomeric butene pyrolysis in Chapter6. The kinetic model is developed for further simulating the pyrolysis of n-butane. The details of the n-butane pyrolysis are illustrated by the ROP and SEN analysis. Meantime, the comparison among n-butane and the three butene isomers are presented.In the last chapter, the pyrolysis of i-butane is investigated. A detailed kinetic model consisting of76species and254elementary reactions was developed to simulate the pyrolysis processes, which can explain the five fuels (1-butene,2-butene, iso-butene, n-butane and iso-butane) at the same time. The mole fraction profiles of pyrolysis species predicted by the model are in good agreement with the experimental measurements. ROP and SEN analysis depict the whole picture of the i-butane pyrolysis. This chapter focus on the comparison of the five fuels.