Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “DIRECT ENERGY CONVERSION”

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.

At least 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Cost-effective Manufacturing and Morphological Stabilization of Nanostructured Cathodes for Commercial Solid Oxide Fuel Cells (SOFCs) [Slides]

The overall goals of the program were to develop methods for preparing and stabilizing SOFC electrodes by infiltration that can be manufactured on a practical scale, then transfer those methods to cells in stacks. Cathodes prepared by infiltration of nanoparticles into a porous scaffold of the electrolyte have demonstrated outstanding electrochemical performance and mechanical strength but are difficult to manufacture due to the large number of infiltration steps required to produce a conductive composite and show poor stability due to sintering of the nanoparticles. At Penn, the main goal was to develop a fabrication method that uses only a small number of infiltration steps. Infiltration with molten salts and electrodeposition were pursued but deemed impractical. A method in which an electronically conductive scaffold consisted of a composite of a mixed conductor, LSF (La 0.9 Sr 0.1 FeO 3 ), with yttria-stabilized zirconia (YSZ) was found to be promising. While some cation mixing between LSF and YSZ was observed during calcination, there was no evidence for new phases in XRD and incorporation of Zr into the perovskite could be minimized by reducing the Sr content of the LSF. To stabilize nanoparticles infiltrated into the LSF-YSZ composite scaffold, the USC team examined the effects of Atomic Layer Deposition with ZrO 2 and infiltrated nanoparticles. Significantly enhanced stability was observed with the infiltrated nanoparticles. The FuelCell Energy team prepared 4”x4” cells in which an LSF-YSZ composite scaffold was cofired with the YSZ electrolyte and infiltrated with LSCF nanoparticles. Apparently because the LSF-YSZ scaffold layer was very thin in this case, the cation mixing that occurred during calcination resulted in a poor scaffold-electrolyte interface which caused reduced performance.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2021

Development of Chromium and Sulfur Getter for Solid Oxide Fuel Cell (SOFC) System

Under the “real world” SOFC operating conditions, gaseous Cr and S species coexist in air stream. The combined Cr and S effect on the electrochemical poisoning of candidate LSM and LSCF electrodes has been investigated. Electrochemical and structural analysis revealed that the combined Cr and S interactions with the LSCF electrode remains significantly different from those of the individual Cr and S interactions. S reacts with the surface SrO accompanied by morphological changes whereas the hexavalent gaseous Cr species mainly deposit at the LSCF/GDC interface as is the case with Cr-only poisoning. For LSM electrode, the combined interactions of Cr and S remains similar to the sum of individual Cr and S effects as SO 2 reacts with Sr-rich regions of the bulk LSM, while Cr deposits at the electrochemically active sites. The use of getter, consisting of alkaline earth and transition metal oxides, has been proposed as a cost-effective approach to mitigate electrode poisoning. SrMnO 3 (SMO) is suggested as a robust getter material for the co-capture of airborne gaseous S and Cr species entering high-temperature electrochemical systems. The honeycomb getter forms, covered with SMO nanoparticles, were fabricated using dip coating. The SMO getter successfully maintained the electrochemical activity of LSM under the presence of gaseous Cr and S species, validating the efficacy of the getter. Post-test characterization revealed that the absorption of S and Cr contaminants led to the elongation of granular SMO particles, forming SrO nanorods and SrCrO 4 whiskers leaving Mn oxides underneath where inward-migrating Cr reside, indicating the high mutual affinity of Sr and Mn. The growth of reaction products during the long term exposure favors continued absorption of incoming S and Cr contaminants. The Mn 2 O 9 dimers, existing on the surface, are considered to help absorb S and Cr impurities, along with the Sr-terminated surface. The SMO getter also displays robust stability in humid environments at high temperatures without phase transformation or hydrolysis, fulfilling the requirement for operation in high-temperature electrochemical systems.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Transformational Solid Oxide Fuel Cell (SOFC) Technology

This project was conducted under the Co-operative Agreement No. DE-FE0027584 with the US Department Energy to developed advanced Solid Oxide Fuel Cell (SOFC) Technologies. The overall objective of this project was to advance SOFC technology at the cell and stack level to enhance cell robustness and durability, increase performance, and reduce balance-of-plant (BOP) requirements. By reducing system complexity combined with the increases in power density and efficiency, the ultimate goal of the project was to increased reliability and to reduce capital and operating costs of installed systems. The project was focused on pathways that will reduce the cost of the SOFC cell and stack, including the following areas: Robust, redox tolerant cell technology Lower cost cell manufacturing through advances in cell design, which will reduce the amount of material, energy and time used in the fabrication of SOFCs High performance, low temperature electrolyte based on improvement of established materials Innovative SOFC stack architecture which truly integrates Balance of Plant functionality into the stack level design Thermal management of the fuel cell stack for increased durability and expanded window of operation Novel stack design amenable for use in sub-MW to multi-MW-scale power plants and having low replacement cost The incorporation of balance-of-plant (BOP) equipment into the stack platform increased the economic viability of smaller scale systems. The project objectives were met by a multi-prong approach, including new cell design complemented with modifications to existing cell technology, as well as a new stack design incorporating components typically included in the BOP, such as heat exchangers, oxidizer, fuel reformers, and recycle systems. The project culminated with demonstration of a stack test validating the viability of the cell and stack improvements. A cost model was also developed to estimate costs for the advanced stack technology at high volume manufacturing levels. The net outcome of the project is SOFC cell and stack technology with costs significantly below current DOE targets without compromising and, in some cases, improving on the performance and degradation rate demonstrated with the current state-of-the-art stack design. The results of this project advanced the reliability, robustness, and endurance of low-cost SOFC technology that ultimately are ready to be deployed in coal power systems with greater than 60 percent efficiency (based on higher heating value of fuel) and the capability for ≥97% CO 2 capture at a cost-of-electricity that is approximately 40 percent below presently available Integrated Gasification Combined Cycle systems.

03 NATURAL GAS↗
DOE OSTI2021

Low-Cost Intermediate-Temperature Fuel-Flexible Protonic-Ceramic Fuel Cell and Stack

Large, centralized power plants are currently the most efficient way to convert fuels such as natural gas to electricity. Fuel cells, however, could become highly efficient generators across a range of sizes from tens of watts to megawatts. In particular, fuel cells with an electrical efficiency of 50% could displace small generators of 25 kilowatts (kW) or less in applications such as remote power, telecommunications, and residential cogeneration. Current 25 kW natural gas generators employing internal combustion engines are typically only 25-30% efficient and expensive to maintain. Furthermore, fuel cells could provide valuable services to the grid, such as the ability to ramp power up or down in response to load conditions. While there are different types of fuel cells, each with their strengths and weaknesses, fuel cells generally are very expensive. For example, lower temperature fuel cells can be started up quickly, but require highly pure hydrogen fuel and expensive catalysts. High-temperature fuel cells can operate on a range of fuels, but they have costly system components and can degrade rapidly.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Prototype Integrated Hydrogen Fuel Cell Powered Data Center (Cooperative Research and Development Final Report)

Data centers are the backbone of the modern economy-from the server rooms that power small- to medium-sized organizations, to the enterprise-class data centers that support American corporations, and the server farms that run cloud computing services. Rather than a traditional grid-centric data center approach, work under the CRADA will be directed towards implementing a proof-of-concept "hydrogen-based" data center utilizing hydrogen fuel cells, electrolyzers, and solar photovoltaics as key building blocks. This integrated proof-of-concept builds on preliminary work done by HPE and its partners Mercedes-Benz Research & Development North America, Inc. (MBRDNA) and Power Innovations, to dramatically simplify the electrical infrastructure in the data center, leverage the latest automotive-scale hydrogen fuel cell technologies, and tightly couple renewably generated DC power directly to the Information Technology (IT). While some limited aspects of this concept have been demonstrated previously the entire integrated proof of concept proposed here has not yet been realized.

08 HYDROGEN↗
DOE OSTI2021

Cooperative Research and Development Agreement among Ames Laboratory; NexTech Materials, Ltd. dba Nexceris; and National Energy Technology Laboratory [Abstract]

The CRADA focuses on pressurized testing of Nexceris solid oxide fuel cell (SOFC) stacks in a hybrid configuration with a recuperated gas turbine with the ultimate goal of demonstrating efficiencies in excess of 70% (LHV NG). NETL’s cyber-physical approach will be used to develop and test control strategies before installing the Nexceris SOFC stacks to maximize the chances of success. A successful test will represent a demonstration of the Nexceris stack to endure pressures associated with hybrid operation and the first public demonstration of automated hybrid SOFC/GT technology.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Maritime Fuel Cell Generator Project [FY2019]

The objective of this project is the demonstration, and validation of hydrogen fuel cells in the marine environment. The prototype generator can be used to guide commercial development of a fuel cell generator product. Work includes assessment and validation of the commercial value proposition of both the application and the hydrogen supply infrastructure through third-party hosted deployment as the next step towards widespread use of hydrogen fuel cells in the maritime environment.

08 HYDROGEN↗
DOE OSTI2022

Maritime Fuel Cell Generator Project [FY2018]

Fuel costs and emissions in maritime ports are an opportunity for transportation energy efficiency improvement and emissions reduction efforts. Ocean-going vessels, harbor craft, and cargo handling equipment are still major contributors to air pollution in and around ports. Diesel engine costs continually increase as tighter criteria pollutant regulations come into effect and will continue to do so with expected introduction of carbon emission regulations. Diesel fuel costs will also continue to rise as requirements for cleaner fuels are imposed. Both aspects will increase the cost of diesel-based power generation on the vessel and on shore. Although fuel cells have been used in many successful applications, they have not been technically or commercially validated in the port environment. One opportunity to do so was identified in Honolulu Harbor at the Young Brothers Ltd. wharf. At this facility, barges sail regularly to and from neighboring islands and containerized diesel generators provide power for the reefers while on the dock and on the barge during transport, nearly always at part load. Due to inherent efficiency characteristics of fuel cells and diesel generators, switching to a hydrogen fuel cell power generator was found to have potential emissions and cost savings. Deployment in Hawaii showed the unit needed greater reliability in the start-up sequence, as well as an improved interface to the end-user, thereby presenting opportunities for repairing/upgrading the unit for deployment in another locale. In FY2018, the unit was repaired and upgraded based on the Hawaii experience, and another deployment site was identified for another 6-month deployment of the 100 kW MarFC.

08 HYDROGEN↗
DOE OSTI2021

FCET Solid Oxide Fuel Cell Testing and Development: CRADA 526 [Abstract only]

The purpose of the proposed project is for PNNL to test the performance of prototype solid oxide fuel cells (SOFCs) created by FCET. Such testing will provide FCET with independent performance data that can be communicated to potential clients and/or investors. Additionally, PNNL will collaborate with FCET on design changes to improve fuel cell performance. Intellectual property developed in this way will benefit FCET with improved products to market, and PNNL through royalty revenue. The key technology held by FCET is a process to deposit extremely thin layers of oxide materials, from 10-50 nm in thickness. The range of possible materials that can be deposited with their method is broad, but this project will focus on the yttria-stabilized zirconia (YSZ) electrolytes for SOFCs. Thin, gas tight YSZ membranes have been a long-sought target in SOFC research. The thinner the YSZ, the lower the cell resistance, and the higher performance of the cell (or the lower the operating temperature). 10-50 nm would be a major step change in YSZ thickness from the state of the art. PNNL can team with FCET on future R&D projects and push this technology forward to improve energy efficiency and reduce carbon emissions.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

H2@Scale Program Multi-Party Cooperative Research and Development Agreement: California Hydrogen Infrastructure Research Consortium Task (Cooperative Research and Development Final Report, CRADA Number CRD-18-00754)

Many stakeholders are working on hydrogen and fuel cell products, markets, requirements, mandates, and policies. California has been leading the way for hydrogen infrastructure and fuel cell electric vehicle (FCEV) deployment. This leadership has advanced a hydrogen network that is not duplicated anywhere in the United States and is unique in the world for its focus on providing a retail fueling experience. In addition, the advancements have identified many lessons learned for hydrogen infrastructure development, deployment, and operation. Other interested states and countries are using California's experience as a model case, making success in California paramount to enabling market acceleration and uptake in the United States. The technical research capability of the national laboratories can be used to assist California in decisions and evaluations, as well as to verify solutions to problems impacting the industry. Because these challenges cannot be addressed by one agency or one laboratory, a hydrogen research consortium has been organized to combine and collaborate. The collaboration aims to ensure that data are available to evaluate projects and inform decision makers, independently verify and validate component solutions, provide experimental results for future hydrogen infrastructure, increase the availability of technical experts for quick-need issues for California hydrogen infrastructure development, deployment, operation, and technology advances. The proposed tasks include data collection from operational stations, component failure fix verification (i.e. nozzle freeze lock), new fueling methods for medium and heavy duty applications, and ensuring hydrogen quality is maintained. U.S. leadership for hydrogen technologies is rooted in California, a location for implementing many H2@Scale pathways such as reducing curtailment and stranded resources, reducing petroleum use and emissions, and developing and creating jobs.

08 HYDROGEN↗
DOE OSTI2021

Rotating Detonation Engine Introduction [Webinar]

Turning a constant pressure combustor into a constant volume combustor changes it from a Brayton Cycle into a Humphrey Cycle. This allows it to extract more work from the fuel, increasing efficiency and reducing emissions. One way to create a constant volume combustor is by using a rotation detonation engine that introduces air and fuel continuously.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Unlocking the Potential of Marine Energy Using Hydrogen Generation Technologies

Marine energy, including ocean waves, ocean currents, ocean thermal gradients, tides, and river currents, is a vast and untapped resource that can be harnessed to help enable the transition to renewable energy. Marine energy is an attractive renewable resource because of its energy density, predictability, and persistence. Further, marine energy has the potential to provide energy for utility-scale applications, remote and distributed applications, and rapidly expanding maritime industries, such as aquaculture and shipping. Marine energy technologies are, however, at a nascent stage of development, and a significant amount of the resource is located far from population centers and transmission infrastructure. Accordingly, to unlock the full potential of marine energy, efficient methods of storing and transporting captured marine energy are needed so that the energy can be used when and where it is needed. A promising solution to these energy storage and transportation challenges is to combine marine energy and hydrogen generation technologies. Herein, we provide a high-level analysis of the unique value proposition and technical challenges of combining marine energy and hydrogen technologies. First, we review marine energy technologies, electrolysis technologies, and hydrogen storage methods. Next, we consider specific applications and opportunities for combining the two technologies. Finally, we identify critical R&D challenges that must be overcome to successfully combine marine energy and hydrogen generation technologies. As part of our fact-finding effort in this area, we held a workshop attended by marine energy and hydrogen technology experts from industry, academia, national labs, and government entities to explore the technical challenges and opportunities for combined marine energy and hydrogen generation systems. Our intent is that this document and the report from the workshop can be used in conjunction to help identify and direct research and development that is needed to realize the potential of marine energy-hydrogen systems.

08 HYDROGEN↗
DOE OSTI2022

High Performance SOFCs with a Superior Stability for Reliable and Durable Power Systems

Next generation of fuel cells, electrolyzers, and batteries requires higher power, faster kinetics, and larger energy density, which necessitate the use of compositionally complex oxides to achieve multifunctionalities and activity. These compositionally complex oxides may change their phases and structures during an electrochemical process – a so-called “electrochemically driven phase transformation”. The origin for such a phase change has remained obscure. More importantly, there is a need to develop high performance solid oxide fuel cells with an enhanced stability. In this work, the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF) cathode surface is modified by infiltration of Pr 6 O 11 and the power density at 0.8V and 750 °C is improved by 21%. In addition, by replacing the traditional barrier layer Gd 0.2 Ce 0.8 O 1.9 with mixed conducting Pr 0.1 Gd 0.1 Ce 0.8 O 1.9 , the power density increases by 38%. The different mechanism of promotions was investigated by electrochemical impedance spectroscopy. The ohmic resistance is dramatically reduced by applying the PGCO interlayer, and the distribution of relaxation time was used to analyze the mechanism for which the polarization resistance was decreased attributing to the mixed conduction nature in PrO x . An increase of power density at 0.8 V of 0.358 W/cm 2 (71%) is achieved with the implementation of both surface modification and buffer layer engineering. An experimental study and a theoretical analysis were then carried out on phase evolution in praseodymium nickelates. Nickelate-based electrodes show up to 60× greater phase transformation during operation when compared to thermally annealed ones. Theoretical analysis suggests that the presence of a reduced oxygen partial pressure at the interface between the oxygen electrode and the electrolyte is the origin for the phase change in an oxygen electrode. Guided by the theory, an addition of the electronic conduction in the interface layer leads to the significant suppression of phase change, while improving cell performance and performance stability. When an oxygen electrode is under polarization, the oxygen partial pressure at the interface between the oxygen electrode and the electrolyte is lower than that of incoming oxidant. Under a high polarization, the environment at the aforementioned interface may lead to phase transformation of the oxygen electrode. The local oxygen partial pressure is determined by the transport properties at the interfaces. An addition of the electronic conduction in the interface layer, for instance using (Pr,Gd)-doped ceria to replace Gd-doped ceria, results in improved cell performance and performance stability, while the phase transformation is significantly suppressed. This work provides a fundamental understanding of the origin for phase transformation in oxygen electrodes during operation and use this knowledge to develop a high-performance electrode that exhibits improved performance stability.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Core-Shell Heterostructures as Functional Materials for Solid Oxide Fuel Cell (SOFC) Electrodes

The principal objective of this project was to synthesize core-shell heterostructures for solid oxide fuel cell cathodes using a molten salt solvent. In doing so, the main goals were split into a) to elucidate and understand the influence of molten salt chemistries to expeditiously synthesize perovskite type oxides for solid oxide fuel cells, b) provide a chemical framework for future molten salt syntheses of energy relevant ceramic materials, c) demonstrate and investigate the required parameters for the optimal core-shell synthesis and yield of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF) – La 0.8 Sr 0.2 MnO 3 (shell), and d) demonstrate improved cathode performance of core-shell LSCF-LSM compared to an LSCF cathode on symmetric cells. The results clearly show that a) the influence of the molten salt cation outweighs the anion in regards to product stoichiometry, b) molten salts should be tailored to balance cationic and anionic acidity for high product yield, c) high yield of core-shell nanoparticles can be achieved by optimal mass ratio between core to shell, dwell time in the salt, size ratio between core to shell, and mass ratio between overall powder to salt, and d) the core-shell LSCF-LSM cathodes have lower polarization resistances than LSCF at higher temperatures. More work is required to optimize core-shell cathode performance at lower temperatures. However, this work thus provided justification for using the molten salt synthesis for SOFC cathodes and provided insights into future material modifications for improved performance.

08 HYDROGEN↗
DOE OSTI2021

Secure Communications Concept and API Concept for Integrating XENDEE Positronix with TESLA PowerPack System at Site 300 (Final Deliverable)

The CleanStart DERMS project focuses on the management of Distributed Energy Resources (DER) for enhanced distribution grid resilience. The demonstration site has changed from Riverside Public Utility to the LLNS Site 300 DERS demonstration site. This project has so far focused only on device level controllers and local area controllers. These controllers potentially lack the ability to perform supervisory control and grid interactive control functions, essential for grid-level optimal DER management. This project seeks to close that gap in development of secure communication concept and appropriate Application Programming Interfaces (API) to enable integration with DERs, device level and local area controllers, such as Distributed Energy Resources Management System (DERMS).

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

Cooperative Research and Development Agreement between National Energy Technology Laboratory and OxEon Energy LLC (Abstract)

The National Energy Technology Laboratory (NETL) will collaborate with OxEon Energy LLC (OxEon) to apply NETL’s patented single step electrode infiltration technique on OxEon solid oxide fuel cells (SOFC) for Electric Vertical Takeoff and Landing (eVTOL) aircraft applications below one megawatt. The expanded application of the OxEon solid oxide cell technology on eVTOL aircraft seeks to demonstrate a high performance, durable SOFC system that will produce more electricity per weight based on possible operation on ammonia as fuel. NETL’s single-step electrode infiltration technique addresses these challenges by introducing a highly active nanocatalyst material into the SOFC electrode microstructure to improving cell performance, longevity, and fuel flexibility. Specifically for this project, OxEon will incorporate NETL’s technology to generate a small stack of cells (1 kW output) to demonstrate a fuel flexible system at a relevant scale. NETL will apply its infiltration technology to cells supplied by OxEon, test the effectiveness of the infiltration internally at NETL based on performance in hydrogen, and then supply infiltrated cells to OxEon and Pacific Northwest National Laboratory for independent confirmation and for the 1 kW stack test.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Techno-Economic Analysis of Integrated Gasification Fuel Cell Systems

This National Energy Technology Laboratory (NETL) study describes the results of a pathway study for coal-based integrated gasification and solid oxide fuel cell (IGFC) power systems with and without carbon capture and storage. Two pathway scenarios are considered, based on the operating pressure of the SOFC. Three gasification technologies, including a conventional technology, differing in the syngas methane content, which has a significant effect on the IGFC system performance, were considered. The performance and cost benefits were estimated for a series of projected gains made through the development of advances in the component technologies or improvements in plant costs and availability. The objective of the study is to provide targeted research and development guidance to the FECM SOFC Program and SOFC commercial developers.

30 DIRECT ENERGY CONVERSION↗