Internal Partial Oxidation Reforming of Butane and Steam Reforming of Ethanol for Anode‐supported Microtubular Solid Oxide Fuel Cells

Abstract

Internal partial oxidation reforming of butane and steam reforming of ethanol were investigated using microtubular solid oxide fuel cells (SOFCs) supported on nickel‐gadolinia doped ceria (Ni‐GDC) anodes for portable power sources in emergency situations and for mobilities, such as vehicles, robots and drones. At an oxygen/carbon (O/C) ratio of 1.0, which is a coking condition in the equilibrium, the Ni‐GDC anode deteriorated for 28 h by internal partial oxidation of butane at 650 °C. However, power generation was also impossible after 8 h and 79 h at steam/carbon (S/C) = 1.0 and 1.5, respectively, by internal steam reforming of ethanol despite of no carbon deposition condition in the equilibrium at 650 °C. Power can be generated for more than 100 h at O/C = 1.5 in butane and at S/C = 2.0 in ethanol. For internal partial oxidation reforming of methane and steam reforming of ethanol in SOFCs, the O/C and S/C ratios are significantly important to prevent carbon deposition on the Ni‐GDC anode.

Ethanol internal reforming in solid oxide fuel cells: A path toward high performance metal-supported cells for vehicular applications

“…To improve internal reforming of ethanol fuel in conventional SOFCs, the primary approach has been to augment or replace the Ni anode electrocatalyst. The most notable catalyst compositions can be classified into four categories: (1) Ni-based anodes such as Ni-YSZ [20,40,41], Ni-GDC [42,43], Ni-CeO2 [44,45], Ni-CZO [46], Ni-BZCYYb [47], Ni-BZCY [22,47], Ni-Al2O3 [22], Ni-SrFeLaCoO3 [48], (2) Ni-free anodes including Cu-CGO [1,41,49], Cu-CeO2 [50,51], Cu-CZO [37], Cu-CeO2-ScSZ [35,52], Ir-CGO [44], Ru-CGO [1], Ru-Cu-CZO [1], Cu-Co(Ru)-CZO [53], Pd-LSCM [54], Ru-LSCM [55], (3) Ni-alloys with Sn [56], Fe [36,48], Co [48,57], and (4) Ni-free alloys such as CuZnAl [58], and CuCoRu [53]. The majority of these studies reported low performance with ethanol (peak power <0.3 W cm -2 at 600-800 ºC), due to the use of inherently low-performing cells, incomplete reforming, or both.…”

Progress in Metal-Supported Solid Oxide Fuel Cells and Electrolyzers with Symmetric Metal Supports and Infiltrated Electrodes

“…Performance with ethanol is of particular interest for consumer vehicles, as a replacement for gasoline. Ethanol can be reformed readily on Ni catalyst, and addition of water reduces the likelihood of coking (14). MS-SOFCs with additional Ni infiltrated into the metal support show excellent performance for direct internal reforming of ethanolwater blend, Fig 5 . Detailed studies of performance with ethanol reformate and internal reforming of ethanol are available elsewhere (15), and durability studies are ongoing.…”

Demonstration of SOFC Power Sources for Drones (UAVs; Unmanned Aerial Vehicles)

“…C 4 H 10 + 2O 2 → 4CO + 5H 2 ∆H 25°C = 316 kJ mol -1 [1] However, the O/C ratio should be more than 1.5 to prevent carbon deposition at 650 o C in the thermodynamic equilibrium (11). Figure 5 shows the current density-voltage and power density characteristics with internal partial oxidation reforming of butane at 650 o C for microtubular cells using Ni-GDC anode.…”