Reaction Kinetics of Glycerol Steam Reforming Using a Ru/Al₂O₃ Catalyst

Abstract

Hydrogen (H2) production by steam reforming represents a candidate method for the utilization of the surplus amounts of biodiesel’s crude glycerol. In this work, reaction kinetics of glycerol steam reforming is studied in a fixed-bed reactor, using a Ru/Al2O3 catalyst. The investigated reaction belongs to the kinetically controlled reaction regime systems. It is found that, in the studied ranges of temperature, 350–500 °C, and W/FAO ratio, 0.4–1.98 g h/mol, the reaction order with respect to glycerol is one. At 500 °C, the first-order reaction rate constant equals 4.2 × 105 cm3/(gcat h). From the temperature dependence of the rate constant, the activation energy (21.2 kJ/mol) is evaluated. Finally, it is found that a heterogeneous kinetic model described in a previous work also suggests first-order kinetics at the low glycerol partial pressures used for this study. Using Ru/Al2O3, we have reported reaction kinetics at low temperatures (T ≤ 500 °C). Our work will facilitate the design and operation of reactors producing H2 from glycerol.