Breakthrough in solid oxide fuel cell technology with direct internal reforming of ethanol: new model offers insight for efficient power generation

Among various fuel cells, SOFCs stand out because of their fuel flexibility, high operating temperatures, and minimal need for precious metals or corrosive materials. SOFCs convert chemical energy directly into electrical energy, achieving over 60% efficiency, far surpassing conventional combustion engines. SOFCs operate by oxidizing fuel with oxygen ions at high temperatures, making them suitable for a range of fuels, including hydrocarbons. A key configuration, direct internal reforming SOFCs (DIR-SOFCs), allows hydrocarbon fuels like ethanol to be reformed directly within the cell, simplifying the system and enhancing performance compared to external reforming configurations.

A study (DOI: 10.48130/emst-0024-0017) published in Emergency Management Science and Technology on 13 August 2024, offers a pathway to more sustainable and resilient energy systems.

The study introduces a new mathematical model tailored for SOFCs using direct internal reforming of ethanol. This model was validated against experimental data, ensuring accuracy in predicting fuel cell performance under varying conditions. By analyzing polarization curves, researchers examined factors such as hydrogen yield and the distribution of species within the fuel cell, revealing how operating conditions influence the reactions inside the SOFC.

The comparison between the model and experimental data showed typical characteristics of high-temperature SOFCs, including negligible activation losses but dominating ohmic losses due to oxygen ion conduction in the electrolyte. Higher operating temperatures improved hydrogen yield and performance at increased current densities, primarily due to reduced ohmic resistance. At low current densities, high temperatures resulted in lower Nernst voltage and overall cell voltage. The simulations also revealed that hydrogen fraction at the anode outlet decreased linearly with current density due to its consumption, while CO fraction decreased and CO₂ fraction increased, driven by the water-gas shift reaction. At 700°C, methane concentration remained nearly unchanged, but at 800°C, some methane was converted to CO through steam reforming. Current density and voltage increased up to 25% along the fuel cell length, driven by the reformation of ethanol, which generated hydrogen to meet demand, but decreased beyond this point as most ethanol had decomposed. This decomposition and subsequent reactions resulted in increased hydrogen, CO, and CO₂ concentrations initially, followed by a decline in hydrogen production and an increase in water content as hydrogen was consumed to generate power, illustrating the complex interplay of reactions within the SOFC.

This study marks a significant advancement in SOFC technology, highlighting the potential of direct internal reforming of ethanol as a game-changer for efficient and flexible power generation. With further refinement and integration of renewable fuels, SOFCs could play a pivotal role in the transition to a low-carbon energy future, addressing both environmental and energy security challenges.

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References

DOI

10.48130/emst-0024-0017

Original Source URL

https://doi.org/10.48130/emst-0024-0017

About Emergency Management Science and Technology

Emergency Management Science and Technology (e-ISSN 2832-448X) is an open access journal of Nanjing Tech University and published by Maximum Academic Press. It is a medium for research in the science and technology of emergency management. Emergency Management Science and Technology publishes high-quality original research articles, reviews, case studies, short communications, editorials, letters, and perspectives from a wide variety of sources dealing with all aspects of the science and technology of emergency.