Performance of bio-char and energy analysis on CH 4 combined reforming by CO 2 and H 2 O into syngas production with assistance of microwave

Abstract The reforming of methane by CO 2 and H 2 O on biomass-derived char (bio-char) was run in a lab-scale microwave oven (2.45 GHz). Special attention was dedicated to the effect of bio-char and energy utilization for the reforming reaction. Through comparing CH 4 conversion from combined reforming and the weighted value of CH 4 conversion from two individual reaction: steam reforming and dry reforming, synergetic effect on CH 4 conversion was confirmed at 900 °C in combined reforming. This effect was attributed to less carbon consumption of bio-char in combined reforming and it was significantly influenced by the contained metal in bio-char. Alkaline metal and alkaline earth metal in bio-char were favorable for improving the conversion of CO 2 and CH 4 , respectively. Through comparison, the mixture of demineralized bio-char and nickel-based catalyst was the most effective to promote combined reforming. Energy efficiency was related to temperature and it was maximized to be 49.2% at 800 °C. The changes of energy efficiency during the reforming process was similar to the variation of CH 4 conversion with time. Specific energy consumption for producing per m 3 of syngas was 4.14 kW·h, with a scale-up microwave-assisted combined reforming process as the model.