Experimental Investigations and Modeling of Direct Internal Reforming of Biogases in Tubular Solid Oxide Fuel Cells

Abstract

Biogas‐fed Solid Oxide Fuel Cell (SOFC) systems can be considered as interesting integrated systems in the framework of distributed power generation. In particular, bio‐methane and bio‐hydrogen produced from anaerobic digestion of organic wastes represent renewable carbon‐neutral fuels for high efficiency electrochemical generators.With such non‐conventional mixtures fed to the anode of the SOFC, the interest lies in understanding the multi‐physics phenomena there occurring and optimizing the geometric and operation parameters of the SOFC, while avoiding operating and fuel conditions that can lead to or accelerate degradation processes.In this study, an anode‐supported (Ni‐YSZ) tubular SOFC was considered; the tubular geometry enables a relatively easy separation of the air and fuel reactants and it allows one to evaluate the temperature field of the fuel gas inside the tube, which is strictly related to the electrochemical and heterogeneous chemical reactions occurring within the anode volume.The experiments have been designed to analyze the behavior of the cell under different load and fuel utilization (FU) conditions, providing efficiency maps for both fuels.The experimental results were used to validate a multi‐physics model of the tubular cell. The model showed to be in good agreement with the experimental data, and was used to study the sensitive of some selected geometrical parameters modification over the cell performances.

Biogas Management: Advanced Utilization for Production of Renewable Energy and Added-value Chemicals

“…This concept, also called direct-biogas solid oxide fuel cell (DB-SOFC), offers several advantages in comparison to the previously discussed method of external reforming (Figure 5), has currently received much attention in both experimental (Goula et al, 2006;Yentekakis, 2006 FIGURE 5 | Schematic of the differences between external (A) and internal (B) reforming concepts for SOFC-added electrical power generation from biogas. Papadam et al, 2012;Takahashi et al, 2012;Lanzini et al, 2013;Ma et al, 2015; and references therein) and modeling studies (Lanzini et al, 2011;Ni, 2013;Janardhanan, 2015a,b). Most of these studies made use of Ni-based cermet anodes, doped with additives in some cases in order to prevent carbon deposition (e.g., Yentekakis, 2006;Ma et al, 2015;Niakolas et al, 2015).…”

Dry Reforming of Methane: Catalytic Performance and Stability of Ir Catalysts Supported on γ-Al2O3, Zr0.92Y0.08O2−δ (YSZ) or Ce0.9Gd0.1O2−δ (GDC) Supports

“…Hence, in order to utilize methane SOFCs plants typically employ an external reformer, where readily available fuels (e.g., CH 4 ) are converted to CO and H 2 , before these efficient fuels are supplied to the fuel cell compartment of the plant. Alternatively, the ''internal'' DRM concept has constantly attained increasing interest in the last years as a more attractive and advantageous design [11][12][13][14][15]. In this concept, the reforming reaction takes place directly-without the need of an external reformer-on the anodic electrode of the fuel cell, simultaneously with the charge transfer (H 2 and CO electro-oxidation by O 2-) reactions, that produce electricity.…”

Thermoelectric characterization of an intermediate temperature solid oxide fuel cell system directly fed by dry biogas

“…There are some articles in the literature in the field of numerical modeling and experimental analysis of SOFC fed by biogas [20][21][22][23][24][25]. In all the simulation models [20,[22][23][24][25] a conventional Ni-YSZ SOFC anode without protective layer is considered, in [20,25] only the anodic electrochemical reaction of hydrogen consumption is considered, in [22][23][24] also the anodic electrochemical reaction of carbon monoxide consumption is considered and only in [23] the anodic electrochemical reaction of methane total oxidation is taken in account.…”

“…In all the simulation models [20,[22][23][24][25] a conventional Ni-YSZ SOFC anode without protective layer is considered, in [20,25] only the anodic electrochemical reaction of hydrogen consumption is considered, in [22][23][24] also the anodic electrochemical reaction of carbon monoxide consumption is considered and only in [23] the anodic electrochemical reaction of methane total oxidation is taken in account. Simulation models in [20,[22][23][24][25] consider only the chemical reactions of steam reforming and water gas shift in the anode.…”