Experimental And Simulation Study On Combined Reforming Of Methane

With increasing attention to energy supply,low carbon and environmental protection,the efficient utilization of natural gas is an important research direction.Combined reforming of methane is of great research value for the efficient conversion of methane through bi-reforming of methane and self-heating.The influence of technological conditions on bi-reforming of methane was investigated by experimental research and simulation calculation.The numerical model of methane autothermal reformer was established,which laid a foundation for the industrial application of combined reforming.Experiments on bi-reforming of methane show that CH4 and CO2 conversion increases with the increase of temperature,and H2/CO decreases accordingly.The methane cracking reaction is more likely to occur,resulting in the reduction of CO selectivity.With the increase of H2O/CH4,the CH4 conversion rate increases,the CO2 conversion decreases rapidly,and H2/CO also increases correspondingly.A kinetic model of methane reformer was established to study bi-reforming of methane reaction process.The results show that CH4,H2O and CO2 conversion increase with the increase of temperature.Compared with the steam reforming of methane,the reaction temperature of the dry reforming of methane is higher.CO2 conversion begins at 650?.With the increase of pressure,CH4,H2O and CO2 conversion all decrease rapidly.When the pressure reaches 3.5 MPa,the conversion rates of CH4,H2O and CO2 are all less than 40%.However,pressure has little effect on H2/CO.At P=3.2 MPa,CO2 conversion increases rapidly at first and then keeps stable with the increase of CO2/CH4.The reaction and flow in the methane autothermal reformer were studied by numerical simulation.The results show that the backflow area in the furnace is small.When the airflow contacts the catalyst bed,the airflow velocity drops rapidly and then tends to be stable.With the increase of the axial distance,the temperature in furnace reaches the maximum value at 2 m.The concentration of the reactants changes greatly when they are in the furnace and just enter the catalytic bed.After entering the catalytic bed,the gas concentration changes slowly because the flow velocity decreases in the catalytic bed and the reaction gradually approaches the equilibrium state.