“Kinetic study of ethanol steam reforming over Ni-Al hydrotalcyte- type catalyst.”

VERÓNICA MAS; GRACIELA BARONETTI; NORMA AMADEO; MIGUEL LABORDE

Turín . Italia

Congreso; Fuel Cells Science and Technology. 2006; 2006

Elsevier

Hydrogen seams to be, in the foreseeable future, a competent energy resource especially to be used in Fuel cell for both stationary and mobiles purpose. Thus, ethanol steam reforming becomes a promising and interesting way to produce hydrogen from renewable sources. In this work, a kinetic scheme reaction under diluted condition is proposed. The experiments were carried out at temperatures ranging from 823 to 923 K using a Ni-Al hydrotalcite-type catalyst. Space time was varied from W/Fethanol=6.7 g cat s/mol  to 25.2 g cat s/mol. To facilitate the fitting of a suitable kinetic expression that enable the design of an ethanol steam reforming reactor, a potential law expression was assumed. To discriminate ethanol and water reaction orders, its respective concentration were varied so that water-ethanol molar ratio ranged from 3.5 to 10. Nevertheless, when water concentration was varied a maximum ethanol conversion was found. Hence, two different reaction orders had to be fitted according to whether water concentration is higher or lower than the concentration in which maximum is produced.  At 900 K the maximum was found to be at a water ethanol molar ratio about  6.5. Both orders were satisfactory fitted being n>0 for values lower and n<0 for higher water ethanol molar ratios. Concerning ethanol order, it was found to be less than one being n=0.7. The pre-exponential factor k and activation energies have been also determined.