Dry (CO2) Reformation of Methane using Nickel-Barium Catalyst

摘要

Methane and CO_2 produced from natural gas wells and biogas plants are potentially efficient for dry reforming to syngas mixture consisting of hydrogen and carbon monoxide. This can help with CO_2 management, provide energy and also serve as a precursor to chemical and liquid fuel production. Syngas produced from dry reforming combined with steam reforming can result in optimal molar ratio of 2 for Fisher-Tropsch synthesis compared to any other reforming processes. Enhanced catalytic conversion using Ni based catalysts provide economic performance but can result in deactivation due to carbon deposition and sintering which calls for modification or promotion of the catalyst. In this paper, the effects of adding alkali barium to Ni-alumina catalyst are investigated to determine the potential of enhanced stability at high conversion. Presence of 2% Ba maintained conversion values similar to Ni catalyst along with reduction of carbon deposition. Addition of Ba revealed reduction in carbon deposition and its effect was not directly proportional to barium content as seen from the results with the addition of up to 4% Ba. Addition of Ba enhanced CO_2 conversion and reduced activation energy of CH_4 and CO_2 but excess (4%) addition of Ba caused significant decrease in conversion and increased activation energy due to the loss of Ni particle dispersion.