Modeling and optimization of the combined carbon dioxide reforming and partial oxidation of natural gas Original Research Article

The optimization of the combined carbon dioxide reforming and partial methane oxidation over a 1% Pt/γ-Al2O3 catalyst was studied in order to produce synthesis gas with hydrogen/carbon monoxide ratio close to 1, for applications in metallurgical and polycarbonates processes and for production of oxygenated compounds and hydrocarbons. The study was performed with the help of experimental design and two mathematical modeling approaches: empirical and phenomenological. Empirical polynomial models were employed to analyze the effects of the process variables on the response factors and the final correlation coefficients obtained were above 95%. The phenomenological model was obtained from individual mass balances and the obtained correlation coefficients were above 95% for CH4 and N2, 90% for CO2 and H2O and near 70% for H2 and CO. The empirical modeling approach was found to be more efficient, simpler and led to better results than those obtained with the phenomenological model approach. Therefore, the empirical modeling was used for optimization of the process operation conditions. At an oxygen/methane ratio of 0.55 gmol/gmol and temperature of 950°C, optimized process conditions were obtained with complete methane conversion, maximum carbon monoxide selectivity of 43% and minimum hydrogen/carbon monoxide ratio of 1.3, in absence of water.