Model biogas steam reforming in a thin Pd-supported membrane reactor to generate clean hydrogen for fuel cells

Steam reforming of a model biogas mixture is studied for generating clean hydrogen by using an inorganic membrane reactor, in which a compositePd/Al2O3 membrane separates part of the produced hydrogen through its selective permeation. The characteristics of H-2 perm-selectivity of the fresh membrane is expressed in terms of H-2/N-2 ideal selectivity, in this case equal to 4300. Concerning biogas steam reforming reaction, at 380 degrees C, 2.0 bar H2O:CH4= 3:1, GHSV = 9000 h(-1) the permeate purity of the recovered hydrogen is around 96%, although the conversion (15%) and hydrogen recovery (>20%) are relatively low; on the contrary, at 450 degrees C, 3.5 bar H2O:CH4 = 4:1, GHSV = 11000 h(-1) the conversion is increased up to more than 30% and the recovery of hydrogen to about 70%. This novel work constitutes a reference study for new developments on biogas steam reforming reaction in membrane reactors. (C) 2014 Elsevier B.V. All rights reserved.