| The growing shortage of fossil fuels makes people pay more and more attention to the exploitation and utilization of natural gas resources.As the main component of natural gas,the conversion and utilization of methane is the key to the conversion of natural gas.Conventional methods of methane conversion have the problems of high activation reaction temperature and easy deactivation of the catalysts,so that the conversion of methane can not be used for industrial production on a large scale.Non-equilibrium plasma activation is a very effective method for molecular activation,and a lot of chemically stable materials can be subjected to a complete chemical reaction under plasma conditions.The current research on plasma assisted methane reforming at home and abroad mainly focus on how to improve conversion of methane and selectivity of the target products by improving the structure of the reactor and changing operation parameters,however,there is little research on the kinetic process of plasma assisted methane reforming.In order to solve this problem,a combination of simulation and experimental research method is used to carry out the following research work in this paper.The experimental platform of plasma assisted methane reforming was established,and the products of plasma assisted CH4 and CH4/CO2 reforming was analyzed quantitatively by gas chromatography.Optical emission spectroscopy（OES）method was used for the diagnostics of species in He/CH4 and He/CH4/CO2 plasmasBased on the experimental data,a detailed kinetic mechanism of plasma reforming of methane at low temperature was established as well as plasma reforming of methane/carbon dioxide.Compared with the experimental results,the kinetic mechanism can accurately predict the methane conversion rate and the change trend of each product selectivity in the methane reforming reaction.Based on the data of electron impact cross section,the electron energy distribution function,mean electron energy and electron energy efficiency in the process of CH4 and CH4/CO2 mixture discharge were analyzed by solving the Boltzmann equation,and some assumptions in the simulation process were verified.The rate of production（ROP）analysis and sensitivity analysis of typical groups and substances in the detailed kinetic mechanism of plasma assisted CH4 and CH4/CO2 reforming were studied.The contribution rate of a elementary reaction to the production and consumption of a certain substance is determined by the rate of production analysis,the sensitivity coefficients were calculated by solving partial differential equations,and the relative importance of each elementary reaction is determined by comparing the order of magnitude of the coefficients.And the kinetic mechanism of the formation of carbon deposition was analyzed in detail,based on the main reaction path of plasma assisted methane reforming,which has been proved in the literature,the reaction pathways of plasma assisted CH4 and CH4/CO2 were obtained combined with the detailed chemical reaction mechanism. |
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