The effect of carbon dioxide in the feed stream of tri-reforming of methane process compared to the partial oxidation of methane.

In this work, we studied the effect of CO2 in the feed stream of the TRM process performance of nickel supported on LaFeO3 perovskite for hydrogen production compared to the POM reaction. The perovskite and nickel supported on LaFeO3 were synthesized and characterized by thermogravimetric analysis (TGA/DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and programmed reduction temperature (TPR). The catalytic tests were carried out in temperatures varying from 700 to 800 °C with feed flow of 350 cm3/min and 200 cm3/min for TRM and POM, respectively. The hydrogen selectivity for the tri-reforming was 78%, while for the partial oxidation reaction, only 55% H2 at 700 °C. Results showed that the hydrogen selectivity for the Ni/LaFeO3 catalyst is significantly higher for the tri-reforming process, suggesting that CO2 enhanced the hydrogen selectivity compared to the partial oxidation of methane. Analyses by Raman spectroscopy and thermogravimetric calculations showed structural modifications of the catalysts after the reaction. The Raman spectrum showed segregated NiO and Fe3O4 and low carbon formation at 700 °C. The proposed mechanism suggests methane and oxygen adsorption, lattice oxygen and CO2 on surface active sites, and vacancies for both reactions.