Plasma-catalytic reforming of CO2-rich biogas over Ni/γ-Al2O3 catalysts in a rotating gliding arc reactor

Abstract

The combination of plasma and heterogeneous catalysis has been considered as an attractive and promising process for the synthesis of fuels and chemicals. In this work, plasma-catalytic reforming of biogas is carried out over Ni/γ-Al2O3 catalysts with different Ni loadings (6 wt.%, 8 wt.% and 10 wt.% Ni) in a novel rotating gliding arc (RGA) plasma reactor. In the plasma reforming of biogas without a catalyst, the CH4 conversion can reach up to 52.6% at a CH4/CO2 molar ratio of 3:7 and a total flow rate of 6L/min. The combination of the RGA with the Ni/γ-Al2O3 catalysts enhances the performance of the plasma biogas reforming: increasing Ni loading enhances the conversion of CH4 and the maximum CH4 conversion of 58.5% is achieved when placing the 10 wt.% Ni/γ-Al2O3 catalyst in the downstream of the RGA reactor. The presence of the 10 wt.% Ni/γ-Al2O3 catalyst in the RGA reactor also increases the H2 yield by 17.6% compared to the reaction in the absence of a catalyst. A comparison of biogas reforming using different plasma technologies shows that the RGA plasma provides a higher conversion, significantly enhanced processing capacity and reduced energy cost for biogas conversion and syngas production. In addition, compared to biogas reforming using other non-thermal plasmas (e.g. dielectric barrier discharge), the RGA reforming process produces much cleaner gas products in which syngas is the major one.