Yttrium-doped barium cerate, BaCe0.85Y0.O-15(3-delta) (BCY15), membranes are proton-conducting electrolytes for intermediate-temperature protonic ceramic fuel cells (IT-PCFC), useful for, among other processes, co-production of power and ethylene by dehydrogenation of ethane. BCY15 membranes showed good conductivity at intermediate temperatures, 15 and 20 mS cm(-1) at 700 and 750 degrees C, respectively. Maximum power density was 174 mW cm(-2) at 700 degrees C, with a corresponding current density of 320 mA cm(-2), using a C2H6,Pt/BCY15/Pt,O-2 fuelcell, with a ca. 0.5 mm thick membrane, producing 34% ethane conversion with 96% ethylene selectivity Comparison of performances using vertical and horizontal set-ups showed that horizontal set-ups are subject to torsional strain, causing reduced cell performance resulting from even minor leakage at the glass seal. (c) 2007 Elsevier B.V. All rights reserved.