The hydrogen refueling station infrastructure is a critical bottleneck that should be addressed for the penetration of the fuel cell vehicles in the automotive sector. The EU co-funded project, “Co-generation of hydrogen, heat and power (CH2P)”, aims to address this by developing a prototype for onsite hydrogen generation from methane rich gas using Solid Oxide Fuel Cells (SOFC). The prototype system will produce 25 kWe electric power and 20 kg of H2/day. It consists of a large SOFC stack module along with necessary balance of plant components. An experimental analysis on the 25 kWe SOFC module is performed to aid the development of the prototype system. The study focuses on understanding the electrochemical performance of the stack towers within the stack module, thermal behavior, such as the temperature distribution among the stack towers and heat losses, and pressure drops

Reactors with solid oxide cells (SOC) are highly efficient electrochemical energy converters, which can be used for electricity generation and production of chemical feedstocks. The technology is in an upscaling phase, demanding development of strategies for robust and efficient operation or large SOC reactors and plants. The present state of the technology requires reactors with multiple stacks to achieve the appropriate power. This study aims to establish and apply a simulation framework to investigate process systems containing SOC reactors with multiple stacks focusing especially on the operating behavior of SOC reactors under transient conditions, by observing the performance of all cells in the reactor. For this purpose, a simulation model of the entire SOC reactor consisting of multiple stacks, pipes, manifolds, and thermal insulation was developed. After validation on stack and reactor level, the model was used to investigate the fundamental behavior of the SOC reactors and the individual stacks in various operation modes. Additionally, the influences of local degradation and reactor scaling on the performance were examined. The results show that detailed investigation of the reactors is necessary to ensure operability and to increase efficiency and robustness. Furthermore, the computing performance is sufficient to develop and validate system controls.

A higher density of large-angle grain boundaries in palladium membranes promotes hydrogen diffusion whereas small-angle grain boundaries suppress it. In this paper, the microstructure formation in 10 µm thick palladium membranes is tuned to achieve a submicronic grain size above 100 nm with a high density of large-angle grain boundaries. Moreover, changes in the grain boundaries’ structure is investigated after exposure to hydrogen at 300 and 500 °C. To attain large-angle grain boundaries in Pd, the coating was performed on yttria-stabilized zirconia/porous Crofer 22 APU substrates (intended for use later in an ultracompact membrane reactor). Two techniques of plasma sprayings were used: suspension plasma spraying using liquid nano-sized powder suspension and vacuum plasma spraying using microsized powder as feedstock. By controlling the process parameters in these two techniques, membranes with a comparable density of large-angle grain boundaries could be developed despite the differences in the fabrication methods and feedstocks. Analyses showed that a randomly oriented submicronic structure could be attained with a very similar grain sizes between 100 and 500 nm which could enhance hydrogen permeation. Exposure to hydrogen for 72 h at high temperatures revealed that the samples maintained their large-angle grain boundaries despite the increase in average grain size to around 536 and 720 nm for vacuum plasma spraying and suspension plasma spraying, respectively.

Defossilization of the global energy system requires a transition towards intermittent renewable energy sources and approaches that enable efficient conversion of primary energy sources into electrical energy. Due to their high efficiency in converting chemical into electrical energy and vice versa, solid oxide cell (SOC) systems provide solutions for both of these aspects. However, mode transitions in SOC operation require operating strategies to ensure that thermal gradients in the reactors are suppressed. In this study, two researched cases utilizing SOC’s are presented, based on simulation studies and experiments with an SOC multi-reactor module. The transient module model is validated in 75 kW electrolysis and polygeneration, and applied to analyze the effect of internal steam methane reforming on the temperature profile of the reactors. Subsequently, it is coupled with a validated Li-ion battery model, to test a rule-based power split control strategy suitable for a demand curve characteristic of a ship.

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