Ni-Mn/γ-Al2O3 assisted plasma dry reforming of methane

The potential for a DBD plasma reactor for methane dry reforming was studied. The plasma dry reforming was carried out by integrating the discharge with a heterogeneous catalyst and the results were compared with plasma reactor alone. For this purpose, NiO/Al2O3 and NiO-MnO2/Al2O3 catalysts were prepared, characterized and integrated with the discharge in an in-plasma configuration. The trend of the CH4 and CO2 conversion, H-2, CO yield, carbon balance and the energy efficiency of the process were analyzed. Typical results indicated that a high conversion was achieved with catalytic DBD compared to plasma alone, whereas, the best syngas ratio was obtained with plasma alone. The highest CH4 and CO2 conversion achieved was similar to 28.4% and similar to 13.2% with 25% packing of the discharge volume. The best yield of H-2 and CO was found to be 7% and 10.5, respectively, whereas the best energy efficiency obtained was 2.76 mmol/kJ with Ni-Mn/Al2O3 packed DBD. The results are correlated by estimating the breakdown voltage, charge, total capacitance and average electron energy for DBD reactor with and without catalytic integration. Optical emission spectroscopy (OES) was employed to understand the active species formed during the dry reforming.