Methane partial oxidation over Ni/Al2O3 based catalyst was studied by conducting a series of consecutive tests varying both catalyst particle size (powder 150 mesh, cylindrical pellets 3 mm diameter) and Ni content (1%÷60%). Also influence of reaction condition was observed as O2/CH4 ratio (0.50÷056) and GHSV (20000÷100000 h-1), defined as the ratio of volumetric flow at standard conditions to the total catalyst volume.
The effects of such parameters on the catalysts activity and stability were investigated and the deactivation as consequence of carbon formation observed. The effect on methane conversion and CO selectivity was studied.
To carry out the experimental tests a micro-reactor with the internal diameter of 9 mm, and about 100 mm of useful length, was used. The micro-reactor, installed inside a furnace, can heated up to 800÷1000 °C. An electro-valve, at the top of the reactor, to control pressure, and mass flow controllers to manage the reactants rate, are provided.
To check the evolution of the reaction all the parameters (pressure, temperature, flows) are monitored and registered and a complete analysis of gas product composition is provided. For this scope two different parallel system are used: a micro-GC unit, for a periodic gas-chromatography analysis, and a multi-component analysis system (thermal conductivity detector, infrared, electrochemical cell) for continuous measurement.
The paper shows the experimental results and the analysis conducted to investigate the behaviour of the methane partial oxidation reaction using non-noble catalysts.