Formulation of steam-methane reforming rate in Ni-YSZ porous anode of solid oxide fuel cells
- 54 Downloads
The steam-methane reforming reaction on a Ni-YSZ (yttria-stabilized zirconia) cermet was experimentally investigated under atmospheric pressure and in the temperature range from 650 to 750 °C. We examined the effects of the partial pressures of methane and steam in the supply gas on the reaction rate. The experiments were conducted with a low Ni contained Ni-YSZ cermet sheet of thickness 0.1 mm. Its porous microstructure and accompanied parameters were quantified using the FIB-SEM (focused ion beam scanning electron microscopy) technique. A power-law-type rate equation incorporating the reaction-rate-limiting conditions was obtained on the basis of the unit surface area of the Ni-pore contact surface in the cermet. The kinetics indicated a strong positive dependence on the methane partial pressure and a negative dependence on the steam partial pressure. The obtained rate equation successfully reproduced the experimental results for Ni-YSZ samples having different microstructures in the case of low methane consumption. The equation also reproduced the limiting-reaction behaviours at different temperatures.
- 2.Xu J, Froment GF (1989) Methane steam reforming, methanation and water-gas shift: I. Intrinsic kinetics AIChE J 35:88–96Google Scholar
- 15.Odegard R, Johnsen E, Karoliussen H (1995) Methane reforming on Ni/zirconia SOFC anodes. Proc. Fourth International Symposium on Solid Oxide Fuel Cells (SOFC-IV), p 810–819Google Scholar