“Hydrogen production from ethanol steam reforming. Fixed bed reactor design.”

GIUNTA PABLO; MIGUEL LABORDE; NORMA AMADEO

Bilbao-España

Simposio; Chemical Reactor Engineering XI. Green Chemical Reactor Engineering; 2007

Hydrogen utilization is the most viable alternative for the future, considering the environmental and sustainability issues related with the energy. Hydrogen is an appropriate environmental solution if it can be obtained from renewable sources. Ethanol is a very good candidate for several reasons: it is renewable and is becoming increasingly available; it is easy to transport, biodegradable and has low toxicity and it is easy to decompose in the presence of water by steam reforming reaction to generate a H2-rich mixture. The ethanol reforming reaction can be represented as: C2H5OH + 3 H2O ↔ 2 CO2 + 6 H2 Nevertheless, this process can occur in several reaction pathways depending on catalyst and reactor conditions. As the catalytic reaction is a heterogeneous gas-solid process and the ethanol conversion rate is very fast, the reaction might be affected by both mass and heat transfer limitations. On the other hand, very few kinetic and reactor design studies have been reported about this reaction. The aim of this work is to perform a simulation of a fixed bed reformer fed with ethanol and water, considering the mass transfer with simultaneous reaction inside the catalyst pellet. An intrinsic kinetics obtained by our group over a Ni/Al2O3 catalyst is employed. In order to take into account the various driving forces acting on each species, the Dusty Gas Model was used. The effectiveness factor was obtained for each species. Plug flow reactor was considered as the fluid dynamic model to size a fixed bed catalytic reactor. The results can be useful to estimate the minimum size of reactor and understanding the sources of performance limitations.