Direct-Flame Solid-Oxide Fuel Cell (DFFC): A Thermally Self-Sustained, Air Self- Breathing, Hydrocarbon-Operated SOFC System in a Simple, No-Chamber Setup

Abstract

We present a combined experimental and modeling study of a direct-flame type solid oxide fuel cell (DFFC). The operation principle of this system is based on the combination of a flame with an SOFC in a simple, no-chamber setup. Experiments were performed using 13-mm-diameter planar SOFCs with Ni-based anode, samaria-doped ceria electrolyte and cobaltite cathode. At the anode, a 7-mm-diameter flat-flame burner provided methane/air rich premixed flames. The cell performance reaches power densities of up to 200 mW/cm2. A detailed analysis of the electrical efficiency is carried out. Observed system efficiencies are below 0.5%. Equilibrium calculations of the flame exhaust gas were performed. From the simulations, both H2 and CO were identified as species that are available as fuel for the SOFC.

Classification of Solid Oxide Fuel Cells

“…However, it has recently been shown that the use of a nanocomposite consisting of materials with different functions as a cathode can significantly increase its selectivity and thereby increase the efficiency of the entire SC-SOFC [ 60 ]. The electrical efficiency of DF-SOFC is even lower (0.45% [ 61 ]), which is associated not so much with the electrode selectivity but with the fact that the fuel is consumed in the combustion reaction. In addition, the significant material stresses arising from thermal load associated with placing the cell near an open flame are a particular problem for DF-SOFC.…”

Techno-Economic Assessment of a Hybrid Gas Tank Hot Water Combined Heat and Power System

“…Therefore, to illustrate the full range of the hybrid systems potential, the fuel utilization was a dependent variable, ranging from 0.4 to 0.9. By using the thermoneutral voltage, defined in Equation ( 17), operating voltage (V), and current generated (i), the heat generated (P h ) from the FFC can be calculated using Equation (18). Current generated can be related to the molar flow rate of syngas supplied to the FFC (v), moles of electrons available to transfer and Faraday's constant as shown in Equation (19).…”

“…Two technologies that have shown promise for mCHP applications are the direct flame SOFC (DFFCs [17][18][19][20]) and flame-assisted SOFC (FFCs [21,22]). These SOFCs utilize partial oxidation as a method to provide the thermal energy needed for operation while reforming the hydrocarbon fuel into hydrogen and carbon monoxide.…”

Catalysis Using Metal Oxides with Mixed Ionic -Electronic Conductivity for Clean Energy Electrochemical Systems

“…However, the major disadvantage of the Ni-based electrode arises from its tendency to coke. Above 700 ͦ C, the active sites of Ni cermets are covered by a filamentous carbon coating [77][78][79]. To prevent coking, other researchers have replaced Ni with various metal oxides or mixed metal oxides, which possess high oxygen anion mobility.…”