(596c) Potential of Ni-Supported Upgraded Slag Oxide Pellets Towards Higher Than Atmospheric Pressure Syngas Production from Methane Reforming

This study explores the H₂-rich syngas production under varying pressures (1-10 atm) at 850 ^oC by dry autothermal and tri-reforming of methane over Ni pellets prepared from metallurgical residue. The influence of process parameters such as reaction pressure, temperature, feed ratio, gas hour space velocity, and role of O₂ circulation across the bed on the conversion of methane and syngas selectivity were investigated. The Ni-supported upgraded slag oxides (Ni-UGSO) pellets consistently showed more resistance to coke formation due to dispersion of Ni in Al, Fe and Mg-based spinels and silicates. The latter influenced positively the activity and catalyst robustness. CH₄ conversions and syngas yields close to equilibrium were reached at pressures between 1 to 10 bar. Typically, a 78% steady CH₄ conversion was obtained for 48 hours during dry autothermal reforming at 10 bar, 850 ^oC under molar ratios of CH₄/O₂ = 2 and CH₄/CO₂ = 3. Similarly, the addition of steam to simulate a tri-reforming condition (CH₄/O₂ = 2 and CO₂:H₂O 1:1) at 10 bar and 800 ^oC has increased the H₂/CO ratio and minimized the coke deposition over longer time on stream. These low-cost and higher-performance Ni-UGSO pellets are a potential candidate for successful and sustainable industrial syngas production, i.e., biogas-to-liquid (BTL) fuel synthesis.