Process simulation and optimisation of H-2 production from ethanol steam reforming and its use in fuel cells. 1 : Thermodynamic and kinetic analysis

Ethanol was considered as raw material for hydrogen production by steam reforming. Reformate purification from CO to feed fuel cells may be accomplished by well established routes, such as high and low temperature water gas shift and methanation, to be integrated with the H2 production unit. A PEM fuel cell can be used for power cogeneration. Data and layout have been inspired by an existing unit Helbio, GH2-BE-5000, capable of delivering 5 kWelectrical + 5 kWthermal output. In order to size and simulate the steam reforming reactor, reliable and complete kinetic data are needed. Partial information has been only found in the literature, in spite of well detailed analysis of the reaction mechanism. In the first part of this work, alternative reaction networks and kinetic models are critically reviewed and compared. Reliable and complete models were applied to literature data to estimate sound kinetic parameters for reactor modeling and simulation, objective of the second part of this work. At first, the equilibrium composition of a reacting mixture was calculated as a function of temperature, pressure and water/ethanol ratio, to define the boundary conditions of this investigation. Then, after selection of three alternative models to represent the complex reaction scheme of bioethanol steam reforming, a full set of kinetic parameters has been estimated and checked for consistency. The latter has been successfully applied to reformer sizing and simulation, as fully described in part 2.