Steam reforming of crude bio-ethanol for hydrogen production over FP catalysts

The production of “bio-hydrogen” is an interesting alternative with respect the traditional production from hydrocarbons. In particular, the production from the bioethanol steam reforming process represent a promising route to improve its sustainability for energy-related purposes. The so-called 2nd generation bio-ethanol, derived from lignocellulosic biomass, such as sorghum, mischantus or poplars possibly growing in marginal lands, appears interesting. Unfortunately, the environmental and energetic impact of next generation biofuels depends on concentration, impurities and operative conditions. In this work two different bioethanol feeds, 50 and 90 vol%, supplied by Mossi&Ghisolfi Group (Proesa process), have been tested for low and high temperature steam reforming. Home-made prepared catalysts were employed in the catalytic tests. Ni was chosen as active phase and several supports were investigate (ZrO2, MxO-ZrO2, La2O3). The Flame Spray Pyrolysis technique was employed for their synthesis. The steam reforming reaction was carried out at several temperature (300°C - 750°C) on a continuous micropilot plant. The effect of impurities was evaluated in term of catalyst performance because deactivation due to long chain alcohols (coke precursors) and sulfur represent key issues. At low temperature the use of bioethanol 90% showed almost the equal H2 productivity (1-1.2 mol min-1 kgcat-1) and ethanol conversion (100%) with respect pure ethanol[1]. By contrast, bioethanol with lower concentration (50%) induced different performance with an increase of coke deposition rate. The acidity of the support was tuned by using several oxidic supports, in order to prevent ethanol dehydration and coking through ethylene polymerization. Fresh and spent samples were characterized by XRD, TPR, TPO, TEM, FE-SEM and Raman analysis. Figure: scheme and image of Flame Spray Pyrolysis References [1] Rossetti, I.; Lasso, J.; Compagnoni, M.; De Guido, G.; Pellegrini, L.; Tian, W.; Wang, Y.; Zhang, H. Chem. Eng. Trans. 2015, 43, 229-234.