SEARCH · Engineering Papers
Results for “Fuel”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Chemistry and transport effects on critical flame initiation radius for alkanes and aromatic fuels
Not Available
Science-based framework for ensuring safe use of hydrogen as an energy carrier and an emission-free transportation fuel
Not Available
Recent development in studies of alternative jet fuel combustion: Progress, challenges, and opportunities
Explore the source record for details and available documents.
Redox and phase behavior of Pd-substituted (La,Sr)CrO3 perovskite solid oxide fuel cell anodes
Not Available
Imaging ionomer in fuel cell catalyst layers with synchrotron nano transmission x-ray microscopy
Explore the source record for details and available documents.
Quantifying the impact of driving style changes on light-duty vehicle fuel consumption
Not Available
Enhancing the Chemical Energy Flux in a High-Temperature Tubular Counterflow Solid Fuel Synthesis Reactor Using a Bypass
Redox reactions of metal oxides offer a path towards using intermittent renewable resources for high-density thermochemical energy storage. Thermochemical energy storage often involves the flow of a particulate media. We describe a novel method to increase the throughput in a gravity-driven high-temperature thermochemical storage reactor flowing pelletized MgMnO. The moving bed reactor operates under counter-flow conditions and encounters particle flowability problems at temperatures of 1500 °C leading to sintering of the bed. Inertial forces of a counter-flowing gas can overcome the gravitational forces on the particles and limit the chemical energy storage rate of the reactor. We found that the insertion of a gas bypass (a slotted tube) into the reactor results in a 100% increase of the flow rates and achieved a 50% higher chemical energy storage flux compared to the operation without a bypass tube while mitigating the effects of sintering on the particles. As a result, the higher solid flow rates require a longer heated zone to reach a comparable residence time and extent of reduction compared to the lower flow rates.
Anion Resistant Oxygen Reduction Electrocatalyst in Phosphoric Acid Fuel Cell
Explore the source record for details and available documents.
High-pressure fast-pyrolysis, fast-hydropyrolysis and catalytic hydrodeoxygenation of cellulose: production of liquid fuel from biomass
Explore the source record for details and available documents.
Evaluation of Cation Migration in Lanthanum Strontium Cobalt Ferrite Solid Oxide Fuel Cell Cathodes via In-Operando X-ray Diffraction
Anode-supported SOFC button cells with LSCF-6428 cathodes were operated at various temperatures under constant current conditions for hundreds of hours in dry or humid (~3% water) cathode air while continuously collecting 1 hour XRD scans throughout the test duration. Additionally, one cell in dry air was held at OCV, and 12% CO2 was added to the humid air for another cell. Long cumulative XRD count times allowed minor phases in concentrations of less than 0.1 wt% to be identified. In humid air, cell performance increased during the first couple of hundred hours. XRD measured a gradual shift of Fe-rich Fe,Co spinel peaks to lower angles while post-mortem SEM discovered nano-nodules on the LSCF surfaces. When 12% CO2 was added to humid air, performance degradation was observed after the initial conditioning response, unlike in tests without CO2, which were stable after conditioning. XRD also measured a shift in the peaks of the major LSCF phase in the test with CO2 indicative of some degree of gradual decomposition. Cells tested at constant current in dry air exhibited fast initial degradation that decelerated over time, while the cell held at OCV maintained a stable voltage. XRD of the cathodes held at OCV at 750 °C and operated at constant current at 700 °C in dry air measured a slower shift of the Fe-rich spinel peaks to lower angles than was seen in tests in humid air, along with a shift in the peaks of a Co-rich Fe,Co spinel to higher angles. Post-mortem SEM of cells exposed to dry air discovered smaller nano-nodules on the LSCF surfaces than had been present in cells tested in humid air. Cells tested at constant current in dry air at 750 °C and 800 °C did not exhibit any gradual changes in the XRD patterns nor were nano-nodules discovered.
Mesoscopic analyses of the impact of morphology and operating conditions on the transport resistances in a proton-exchange-membrane fuel-cell catalyst layer
Exploring the origins of local transport resistance and characterizing the oxygen transport resistances in the catalyst layer (RCL) are critical for cost reduction. In this paper, a comprehensive mesoscopic model for simulating coupled transport processes of oxygen and water vapor for different structural parameters under different operating conditions in reconstructed microstructures is proposed. The local transport resistance is calculated after achieving the limiting current density and the effective diffusivity of oxygen. The results demonstrate that RCL increases greatly with decreasing platinum loading (LPt) and the transport resistances in other components of the cell dominate for high-loadings. Both the reduced oxygen permeation coefficient in the ionomer thin-film and the adsorption resistance account for the origins of local transport resistance. The local transport resistance increases with the bare carbon ratio for a constant LPt and Pt/C ratio due to the decreased effective ionomer surface, and increases with the I/C ratio due to the increased ionomer thickness and decreased Knudsen diffusivity. Due to the presence of liquid water, a slight decrease followed by an increase of the local transport resistance versus relative humidity is obtained. The contribution of ionomer thin-films to RCL is more sensitive to liquid saturation compared with that of pores. This journal is