FLUIDIZED BED CHEMICAL LOOPING PROCESS FOR GREEN SYNGAS PRODUCTION

Methane reforming is an important process for hydrogen production worldwide. The related CO2 footprint can be limited by ether using renewable methane, or recycling carbon dioxide from capture processes. Methane reforming in presence of a catalyst also acting as oxygen carrier was investigated, as an attractive process for production of hydrogen and carbon monoxide mixtures. The distinctive aspect of the research was the development of different granular materials based on CeO2 for utilization under fluidized bed conditions. Two granular materials were composed by CeO2 only, differing by the calcining temperature (900 and 1200°C), whereas a third one was a CeO2 and Al2O3 composite, thermally treated at 1200°C. Fluidization and comminution tests were performed at cold conditions and showed the best attrition resistance of materials calcined at the highest temperature. Conversely, thermogravimetric tests performed at 900 °C revealed the best performance of CeO2 granules with respect to the others in terms of oxygen supply capacity, achieving about 75% of the stoichiometric oxygen transfer capability of the material. Reforming tests in fluidized bed were performed at 900 °C with Ce-Al composite, giving rise to acceptable conversion of methane in syngas, achieving a value up to 80% in the initial time step of the reforming.