Katarzyna Sabolsky

SOFC cells and stacks for complex fuels

Reformed hydrocarbon and coal (syngas) fuels present an opportunity to integrate solid oxide fuel cells into the existing fuel infrastructure. However, these fuels often contain impurities or additives that may lead to cell degradation through sulfur poisoning or coking. Achieving high performance and sulfur tolerance in SOFCs operating on these fuels would simplify system balance of plant and sequestration of anode tail gas. NexTech Materials, Ltd., has developed a suite of materials and components (cells, seals, interconnects) designed for operation in sulfur-containing syngas fuels. These materials and component technologies have been integrated into an SOFC stack for testing on simulated propane, logistic fuel reformates and coal syngas. Details of the technical approach, cell and stack performance is reported.

Gasifier Health Monitoring using Smart Refractory Bricks

The short life of the refractory lining in the slagging gasifier is a major concern leading to high operating cost and low availability. For prolonging the life of the refractory lining, it is important to monitor its health. Two key variables for monitoring the health of the gasifier refractory are the temperature profile both in the axial and radial directions along the wall and the extent of slag penetration in the wall. However, stateof- the-art measurement techniques are inadequate for the harsh gasifier environment. In this paper, a novel approach is considered where sensors embedded in a brick, denoted as the smart refractory brick, is used to estimate these two variables. Typical approaches, where correlations between the raw measurements (such as the voltage, current, etc.) and the variables of interest (such as the temperature) are used, are inadequate due to the high spatial temperature gradient along the wall and time-varying material properties. In this paper, a model-based estimation approach is developed to address this issue. Issues with the out-of-sequence measurements in the estimation framework are addressed.

Direct foamed and nanocatalyst impregnated SOFC cathodes

A binder system containing polyurethane precursors was used to in situ foam (direct foam) an (La 0.6 Sr 0.4 ) 0.98 (Co 0.2 Fe 0.8 )O 3−δ (LSCF) cathode composition on an yttrium-stabilised zirconia (YSZ) electrolyte coated with a porous ∼10 µm thick cathode active layer. The YSZ electrolyte was ∼110 μm thick, and a fuel cell was created by application of a Ni/(Ce 0.9 Gd 0.1 )O 2 cermet as the baseline anode. Cells possessing the foamed LSCF cathode were compared to cells constructed via standard methods in terms of resultant microstructure, electrochemical performance, and introceptive character. The foamed cathode tended to possess a high level of tortuous porosity which was ellipsoidal and interconnected in character. Both the standard and foamed cathode structures were subjected to an infiltration process, and the resultant microstructure was examined. The impregnation efficiency of the foamed cathode was at least ∼10% greater per deposition than that of an unfoamed porous LSCF cathode. The SOFC with the Pt nanocatalyst impregnated foamed cathode demonstrated a maximum power density of 593 mW/cm 2 utilising wet H 2 fuel, which is 52% higher than an SOFC with the baseline Pt-impregnated LSCF cathode (∼390 mW/cm 2 ) at 800°C. The cathode compositional and microstructural alterations obtainable by foaming led to the elevated power performance, which was shown to be quite high relative to standard SOFCs with a thick YSZ electrolyte.