Study On Biogas Reforming To Synthesis Gas By Plasma-induced

Biogas which includes a great number of methane(CH4) and carbon dioxide(CO2), can be served as the gas of raw materials for CO2 reforming of CH4 to produce synthesis gas(syngas), so the technology of CO2 reforming of CH4 can enable the quality of the biogas to be improved, and the emission of greenhouse gas(CO2) can be reduced at the same time. However, the conventional CO2 reforming of CH4 has a lot of shortages such as the deactivation of catalyst because of carbon deposition and the high reaction temperature, so the technology of CO2 reforming of CH4 is difficultly applied in the reality. In contrast, under the assistance of non-equilibrium gliding arc plasma, CO2 reforming of CH4 to syngas can successfully become the reality.For corresponding the existing problems, gliding arc plasma is creatively applied in the process of biogas reforming to syngas so as to make a solid foundation for the value-added utilization of biogas. Through the utilization of gliding arc reactor of knife-type electrodes, CO2 reforming of CH4 to syngas was systematically investigated in this paper. Firstly, the effects of different reaction conditions of biogas reforming on the basic characteristics of gliding plasma discharge were studied; Secondly, the effects of different inputting voltages and reaction time on the biogas reforming were also studied; At last, through above the researches, the mechanisms of CO2 reforming of CH4 by the assistance of gliding arc plasma were obtained. What’s more, the improving gliding arc discharge device induced biogas reforming to syngas was also studied.Therefore, the main conclusions are drawn as follows:(1)The increase of flow rate of inputting gas can cause the increase of average arc voltage and average arc power. The optimum flow rate of gas is 5-7L/min in this study, which is suitable for the process of biogas reforming. The electrode gap and electrode thickness also have the important impact on the discharge characteristics of gliding arc plasma. It’s indicated that the discharge effect is best when the electrode thickness and electrode gap is 2mm and 2-3mm respectively.(2)With the increasing of inputting voltage, the reforming performance of gliding arc reactor is increased significantly so that the conversion rates of CH4 and CO2 are increased by 28.55% and 24.76%, respectively. When the reaction time is 75 min, CH4 and CO2 are closed to be completely transformed.(3)With the increasing of inputting voltage and reaction time, the concentration of plasma in the reactor is also essentially increased. So the electrons are coupled with more energy, and the number of high energy electron, ions and free radicals are also increased, which enable collision and ionization of the gas molecules more thoroughly in the whole reacting system.(4)Because the plasma area of knife-type of gliding arc discharge reactor is greater than the new type gliding arc discharge reactor, comparing with the knife-type gliding arc discharge induced biogas reforming, new type gliding arc discharge will consume more energy to generate unit volume of syngas.