Configuration Development of Autothermal Solid Oxide Fuel Cell: A Review

Abstract

Solid Oxide Fuel Cell (SOFC) is typically operated at high temperature. Both electricity and heat are generated during operation. Therefore, SOFC can be efficiently designed to integrate the endothermic reformer with the cell for optimizing heat utilization, as called autothermal operation. However, the mismatch between rate of exothermic electrochemical reaction and endothermic reforming reaction is easily resulted in material cracking of that integrated structure. In order to overcome the thermal mismatch limitation, various approaches for autothermal SOFC configurations have been widely developed; these configurations can be classified into 2 main groups including direct internal reforming (as called DIR-SOFC) and indirect internal reforming (as called IIR-SOFC) operations. This review focuses on the technological progress of these various configurations. In detail, the thermal behavior inside each autothermal SOFC configuration is explored. The effect of different primary hydrocarbon fuels on temperature distribution in the autothermal SOFC structures is also indicted. In addition, the advantage and disadvantage on thermal stress reduction of each configuration are also discussed. The historical of this development would advantage for further system modification and scale up to desired power output

Catalytic Steam Reforming of Natural Gas over a New Ni Exsolved Ruddlesden‐Popper Manganite in SOFC Anode Conditions

“…S j ¼ f j n Out j P N i¼1 f i n In i À n Out i ð Þ dimensionless (8) Finally, H 2 to CO ratio was defined by Equation (9).…”

“…Where, W Cat is the catalyst weight (g), n In C n H 2nþ2 and n Out C n H 2nþ2 are the individual light hydrocarbons molar flow rate at the inlet and outlet of the reactor (mmol min À 1 ) and n Out H 2 is the H 2 molar flow rate at the outlet of the reactor (mmol min À 1 ). Besides, the selectivity S j À � to CO, CO 2 , C 2 H 4 , C 2 H 6 , and C 3 H 6 , were defined as the ratio between the molar flow rate of all carbon atoms in the outlet of the selected j product and, that of the reacted light hydrocarbons i employed as reactants as shown in Equation (8), where ϕ is the carbon number of the selected j product or i reactive and n the molar flow rate.…”

“…Colombian natural gas (Cusiana) composition. [6] Cusiana gas (Colombia) Compounds Composition [%mol] CH 4 82.195 C 2 H 6 10.841 C 3 H 8 3.510 CO 2 1.900 Minority hydrocarbons 1.035 N 2 0.519 H 2 S 2-50 ppm Shift (WGS) reaction represented as Equation (2). However, the overall reaction is the Methane overall steam reforming (Equation (3)) that is globally highly endothermic.…”

“…[3] There are four different ways to consider the hydrogen (H 2 ) production from hydrocarbon fuels and avoid carbon deposition: dry reforming (with CO 2 ), steam reforming (with H 2 O), partial oxidation (with O 2 ) and autothermal reforming (with steam and O 2 ). [7][8][9][10][11][12] Each process is achieved under different operating conditions and any or all of them could be selected to study the behavior of a specific anode material in a catalytic way. However, according to the literature, water vapor has been considered as a particularly relevant component to be mixed to methane; steam to carbon ratios (S/C) higher than 1.0 are generally necessary to avoid the coke formation on the anode surface, making steam reforming one of the most important reaction taking place at the anode surface.…”

Ceramic Protective Coatings for Cordierite-Mullite Refractory Materials

“…Low-temperature SOFCs which operate at 573-873 K are known as very suitable for direct biofuels application, since most biofuels can thermally crack into H 2 and CO 2 , in which H 2 production may support fuel cell performance. In DE-SOFC, the ethanol fuel is changed to gas, whether through an external or internal reforming gas [6]. In an external reforming, liquid fuel vaporizes in an external high-temperature system.…”