Biogas reforming for hydrogen-rich syngas production over a Ni–K/Al2O3 catalyst using a temperature-controlled plasma reactor

Plasma-enhanced catalytic biogas reforming for hydrogen-rich syngas production over a Ni–K/Al2O3 catalyst was investigated using a tabular dielectric barrier discharge non-thermal plasma reactor. To better understand the plasma catalysis synergy at elevated temperatures, we compared different reaction modes: plasma catalysis, plasma alone, and catalysis alone in a reaction temperature range of 160–400 °C. The combination of Ni–K/Al2O3 and plasma produced synergistic effects. Notably, the plasma-catalytic synergy was temperature-dependent and varied at different reaction temperatures. Using plasma catalysis, the maximum conversion of CH4 and CO2 (31.6% and 22.8%, respectively) was attained over Ni–K/Al2O3 at 160 °C, while increasing the reaction temperature to 340 °C noticeably enhanced the H2/CO ratio to 2.71. Moreover, compared to plasma-catalytic biogas reforming at 160 °C, increasing the reaction temperature to 400 °C suppressed biogas conversion with dramatically reduced coke formation on the Ni–K/Al2O3 surface from 6.81 wt% to 3.37 wt%.