Applied Catalysis A: General, Vol.550, 176-183, 2018
Coupled reforming of methane to syngas (2H(2)-CO) over Mg-Al oxide supported Ni catalyst
We report bi-reforming and coupled reforming of methane with carbon dioxide, steam and/or oxygen to produce syngas over Ni supported on Mg-Al mixed oxide. The catalyst has been characterised in terms of specific surface area, TPR, XRD, TGA-DTG, SEM and TPO-MS analysis. Ni/Mg-Al mixed oxide exhibited Ni particle size range (11-30 nm) with a mean of 20.7 nm. Syngas H-2/CO = 2.0, suitable for methanol/Fischer-Tropsch fuel synthesis, has been achieved for both reactions (T = 1048 K, P = 1 atm). The impact of process parameters including temperature, feeding concentration and GHSV on conversion and H-2/CO ratio has been demonstrated. The Ni catalyst suffered temporal activity decline in bi-reforming that can be linked to formation of carbon whiskers encapsulated Ni particles resulting in a loss of active sites. Coupled reforming delivered higher CH4 conversion and enhanced stability, but lower CO2 conversion than bi-reforming under similar conditions. The enhanced stability in coupled reforming can be attributed to lower carbon deposition on Ni particles due to combustion of carbon by oxygen.