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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.

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At least 235 records · Page 13

Concentrated solar thermal fuels production by electric field enhanced two step gas splitting (Final Technical Report)

Solar thermochemical CO 2 splitting (STCS) is plagued by high solar field costs due to the extraordinarily high temperatures (~1500 °C) required. In STCS, a reduction/oxidation active material, CeO 2 , is thermally reduced to CeO 2-δ generating O2 at ~1500 °C; then CeO 2-δ is re-oxidized by CO 2 to re-form CeO 2 and CO, a precursor to liquid fuels. Before this project, there were no known methods to decrease the reduction temperature while maintaining high conversion of the CO 2 to CO; thus, projected solar thermal CO costs had stagnated.

10 SYNTHETIC FUELS↗

Impact of a Novel Nickel-Based Catalyst and Phenyl-Acrylate-Based Anion-Exchange Membrane in a Direct Urea Fuel Cell

Developing target-specific catalysts and anion-exchange membranes (AEMs) is crucial for direct urea fuel cell (DUFC) performance. To advance the DUFC system, we developed an anode catalyst with a nickel–iron oxyhydroxide/carbon (NiFeOOH/C) nanofibrous structure for the urea oxidation reaction (UOR), where we optimized the Ni/Fe molar ratio as 6:4. The enhanced electrocatalytic activity of the anode (Ni 6 Fe 4 OOH/C) is attributed to the hydroxide group, which responds with urea molecules to enhance the UOR in a pH-neutral system. Here, we employed a recently developed cross-linked phenyl-acrylate-based AEM (PA/M). A DUFC prepared with the anode and PA/M generates a maximum power density of 11.1 mW/cm 2 and 0.92 V open-circuit voltage under 3 M urea as fuel at 25 °C. We further analyzed the applicability of PA/M in a DUFC system by measuring the urea partition coefficients and permeabilities over a range of concentrations.

10 SYNTHETIC FUELS↗

Reliability and Durability Testing of Glass Ceramic Seals for Praxair’s Oxygen Transport Membranes

Praxair has been developing Oxygen Transport Membrane (OTM) systems for the efficient conversion of natural gas to syngas which can subsequently be used in chemical synthesis, generation of industrial gases (H2, CO) or synthesis of liquid fuels. One of the technical barriers for commercialization of this technology is the reliability of key components of OTM systems – Seals and Membranes. Praxair has been testing these components at the process conditions expected for commercial systems. However, long-term durability data is currently limited and is not sufficiently available to make well informed predictions of OTM reliability which represents one of the major risks that could prevent the technology from being fully commercialized. Pacific Northwest National Laboratory (PNNL) has been developing high temperature seals and ceramic membranes for applications similar to OTM systems such as Solid Oxide Fuel Cells. The goal of the cooperative development between Praxair and PNNL is to generate long-term data such that there is sufficient confidence in the OTM seal and membrane reliability predictions to enable the process technology to be fully commercialized.

03 NATURAL GAS↗

Electrochemical conversion of coal-derived CO 2 into fuels and chemicals using a modified PEM electrolyzer. Final report

Opus 12 is developing an electrochemical process to convert CO 2 into chemicals and fuels. Using only CO 2 , water, and electricity as inputs, the electrochemical reduction of CO 2 could form the basis of an artificial carbon cycle that replaces a wide range of products that are currently derived from fossil fuel resources. We have developed a prototype that demonstrates high selectivity and current density for CO 2 conversion to CO, which can be used to make high-value products including methanol, acetic acid, polymers, and pharmaceuticals.

01 COAL, LIGNITE, AND PEAT↗

Staged OMB for Modular Gasifier/Burner

The goal of this final project report is to comprehensively summarize the work conducted on project DE-FE0031506. In accordance with the Statement of Project Objectives (SOPO), the University of Kentucky Center for Applied Energy Research (UK CAER) (Recipient) has developed a staged opposed multi-burner (OMB) gasifier, scaled down from a commercial gasification technology to utilize coal slurry as feed for the high-temperature gasification. The project involved the design, fabrication, commissioning, parametric testing, and performance validation of the entrained gasifier with multiple burners to narrow the major near-term technical gaps that impede the application of small-size gasification by modularizing the system. Project results verified the UK CAER approach to address the major technical challenges on the gasification modularization for a distributed application at a small scale of 1-5 MWe, while maintaining advantages in cost and flexibility, which include: 1) a cost-effective burner configuration to provide high flexibility in both load and fuel feed; 2) the modularized staged-OMB to provide better gasification performance such as a desired temperature profile, better fuel conversion, better gasification efficiency, and long lifetimes of the refractory wall and burners; and 3) load control simply through changing the number of burners firing. UK CAER’s staged gasifier configuration, fuel blend performance, and economic evaluation shows promise, as summarized in this report, as an effective means for improved gasification efficiency with reduced operation cost and process complexity.

01 COAL, LIGNITE, AND PEAT↗

Proton transfer kinetics of transition metal hydride complexes and implications for fuel-forming reactions

Proton transfer reactions involving transition metal hydride complexes are prevalent in a number of catalytic fuel-forming reactions, where the proton transfer kinetics to or from the metal center can have significant impacts on the efficiency, selectivity, and stability associated with the catalytic cycle. Here, this review correlates the often slow proton transfer rate constants of transition metal hydride complexes to their electronic and structural descriptors and provides perspective on how to exploit these parameters to control proton transfer kinetics to and from the metal center. A toolbox of techniques for experimental determination of proton transfer rate constants is discussed, and case studies where proton transfer rate constant determination informs fuel-forming reactions are highlighted. Opportunities for extending proton transfer kinetic measurements to additional systems are presented, and the importance of synergizing the thermodynamics and kinetics of proton transfer involving transition metal hydride complexes is emphasized.

08 HYDROGEN↗

Accelerating Combustion and Surface Chemistry Simulations

Design of modern combustion systems relies on computer models to predict how changes in design will affect performance. These models have largely displaced previous methods that rely on the designer’s intuition or costly and time-consuming physical testing. By using improved models, design cycles can be shortened, and cleaner and more efficient combustion devices can be created. This project aims to improve computer simulations of transportation fuels with the goal of making these simulations faster and more accurate for predicting combustion in vehicles.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Error quantification of the Arrhenius blending rule for viscosity of hydrocarbon mixtures

Six hundred and seventy-five measurements of dynamic viscosity and density have been used to assess the prediction error of the Arrhenius blending rule for kinematic viscosity of hydrocarbon mixtures. Major trends within the data show that mixture complexity–binary to hundreds of components—and temperature are more important determinants of prediction error than differences in molecular size or hydrogen saturation between the components of the mixtures. Over the range evaluated, no correlation between prediction error and mole fractions was observed, suggesting the log of viscosity truly is linear in mole fraction, as indicated by the Arrhenius blending rule. Mixture complexity and temperature also impact molar volume and its prediction. However, a linear regression between the two model errors explains less than 20% of the observed variation, indicating that mixture viscosity and/or molar volume are not linear with respect to temperature and/or mixture complexity. Extensive discussion of the intermolecular forces and the geometric arrangement of molecules and vacancies in liquids, which ultimately determines its viscosity, is brought into context with the implicit approximations behind the Arrhenius blending rule. The complexity of this physics is not compatible with a simple algebraic correction to the model. However, sufficient data is now available to determine confidence intervals around the prediction of fuel viscosity based on its component mole fractions and viscosities. At -40°C, when all identified components are pure molecules the modeling error is 13.2% of the predicted (nominal) viscosity times the root mean square of the component mole fractions.

10 SYNTHETIC FUELS↗

Higher Energy-Content Jet Blending Components Derived from Ethanol (CRADA 467)

This project aims to develop a new sustainable aviation fuel (SAF) that comprises favorable properties, such as high energy density, excellent thermal stability, and favorable cold fold properties. Through catalyst development, this work will provide a route to control the cycloalkane/n-alkane/iso alkane content of a next-generation fuel with minimal or no aromatic content. Combining n-alkane and iso-alkane streams (high specific energy, MJ/kg) with cycloalkanes (higher energy density, MJ/L), is expected to enable at least a 4% net increase in combined (specific (MJ/kg) and volumetric (MJ/L)) energy content without impacting ‘drop-in’ fuel requirements, such as seal swelling. PNNL and LanzaTech have already demonstrated a sustainable, non-petroleum, route to isoalkanes. However, economically attractive cycloalkane production from waste and biomass is challenged by large hydrogen requirements, preferential selectivity to aromatic compounds and low yields to jet fuel range components. Many gaps in understanding cycloalkane properties and performance in complex jet fuel mixtures remain. The close tie and integration of Purdue’s fuel property analysis, with PNNL’s process development, can lead to an economically attractive process. The fuel analysis and testing by Purdue will enable a robust understanding of the properties and behavior of the cycloalkanes produced to inform process development. Additionally, seal-swelling analysis will quantify the ability of fuel blends with zero or minimal aromatics content to satisfy the seal swell requirement of O rings. Lastly, Purdue’s system-level analysis will lead to the development of a roadmap for deployment in key regions that considers system pressures such as hydrogen, water, energy efficiency, and ease of infrastructure access.

10 SYNTHETIC FUELS↗

Abstract for CRADA between National Energy Technology Laboratory and Malachite Technologies, Inc.

The National Energy Technology Laboratory (NETL) and Malachite Technologies, Inc (MTI) will collaborate in the demonstration of early-stage feasibility of a process which will produce JP-10 fuel compliant with Mil Spec MIL-DTL-87107E. Our process will convert, by means of a plasma reactor, carbon dioxide (CO 2 ) feedstock which, along with hydrogen, will serve as a feedstock for an integrated Fischer-Tropsch (FT) reactor. A customized zeolite catalyst will support a highly selective production of JP-10 in the FT reactor.

10 SYNTHETIC FUELS↗

Life cycle greenhouse gas emissions of ethanol produced via fermentation of sugars derived from shrub willow (Salix ssp.) hot water extraction in the Northeast United States

Abstract Background The amount of carbon dioxide in the atmosphere has been on the rise for more than a century. Bioenergy crops are seen by the Intergovernmental Panel on Climate Change as an essential part of the solution to addressing climate change. To understand the potential impact of shrub willow ( Salix spp . ) crop in the northeast United States, effective and transparent life cycle assessment of these systems needs to occur. Results Here we show, ethanol produced from the fermentation of sugars from hot water extract of willow grown on cropland can sequester 0.012 ± 0.003 kg CO 2eq MJ −1 for a supply system incorporating summer harvest and storage. Despite decreases in soil organic carbon when willow is instead grown on grassland, the produced fuel still can provide significant climate benefits compared to gasoline. Conclusions Shrub willow converted to ethanol can be a carbon negative source of transportation fuel when the electricity and heat required for the conversion process are generated from renewable biomass. The sequestration of carbon in the belowground portion of the plants is essential for the negative GHG balance for cropland and low GHG emissions in grassland.

10 SYNTHETIC FUELS↗

Conversion of syngas into light olefins in one step for process-intensified production of sustainable aviation fuels

Here, we report on a preliminary investigation for direct conversion of syngas into olefins. This technology combines alcohol(s) production and olefin(s) production into a single unit operation to improve process efficiencies due to the overcoming of equilibrium limitations and also to offer capital savings relative to current synthesis approaches including Fischer-Tropsch synthesis, methanol-to-olefins followed by olefins to gasoline/distillate process and alcohol-to-jet process.

10 SYNTHETIC FUELS↗

Hybrid Fuel Cell—Supercritical CO2 Brayton Cycle for CO2 Sequestration-Ready Combined Heat and Power

The low prices and its relatively low carbon intensity of natural gas have encouraged the coal replacement with natural gas power generation. Such a replacement reduces greenhouse gases and other emissions. To address the significant energy penalty of carbon dioxide (CO2) sequestration in gas turbine systems, a novel high efficiency concept is proposed and analyzed, which integrates a flame-assisted fuel cell (FFC) with a supercritical CO2 (sCO2) Brayton cycle air separation. The air separation enables the exhaust from the system to be CO2 sequestration-ready. The FFC provides the heat required for the sCO2 cycle. Heat rejected from the sCO2 cycle provides the heat required for adsorption-desorption pumping to isolate oxygen via air separation. The maximum electrical efficiency of the FFC sCO2 turbine hybrid (FFCTH) without being CO2 sequestration-ready is 60%, with the maximum penalty being 0.68% at a fuel-rich equivalence ratio (Φ) of 2.8, where Φ is proportional to fuel-air ratio. This electrical efficiency is higher than the standard sCO2 cycle by 6.85%. The maximum power-to-heat ratio of the sequestration-ready FFCTH is 233 at a Φ = 2.8. Even after including the air separation penalty, the electrical efficiency is higher than in previous studies.

10 SYNTHETIC FUELS↗

Final Science Report of the Joint Center for Artificial Photosynthesis (JCAP)

The Joint Center for Artificial Photosynthesis (JCAP) was designated as the U.S. Department of Energy (DOE) Fuels from Sunlight Energy Innovation Hub on July 22, 2010, and began operations according to a cooperative agreement between the DOE and the California Institute of Technology on September 30, 2010. The cooperative agreement was renewed on September 30, 2015. This final science report outlines JCAP research activities from September 30, 2010 to September 30, 2021.

08 HYDROGEN↗

Increasing CO2 Conversion Efficiency with Optical Thermal Management in Concentrated Solar Reactors: New Dual-Stage Solar Reactor Design for Reduction of CO2 to Fuels

The proposed project will result in a new dual-stage solar chemical reactor designed to convert carbon dioxide (CO2) to value-added chemicals. Using sunlight as the main power source, a sustainable process will be developed that closes the loop on our industrial carbon cycle in an energy efficient and environmentally friendly manner. The hybrid photochemical and photothermal reactor design will vastly increase utilization of the solar spectrum and increase CO2 conversion efficiencies over Dimensional Energy’s current state-of-the-art.

10 SYNTHETIC FUELS↗

Direct conversion of syngas to lower olefins precursors of jet fuel and chemicals

This study investigates the direct conversion of syngas to olefins as a pathway to produce sustainable aviation fuels. This approach combines methanol/ dimethyl ether synthesis with methanol-to-olefins into one unit operation to avoid the equilibrium limitation of methanol synthesis and the Anderson–Schulz–Flory distribution limitations from the Fischer Tropsch process. The ability to combine reactor functionalities into a single step are also projected to significantly lower capital costs over current synthesis approaches for the syngas to olefins process.

10 SYNTHETIC FUELS↗

Cradle-to-Grave Lifecycle Analysis of U.S. Light-Duty Vehicle-Fuel Pathways: A Greenhouse Gas Emissions and Economic Assessment of Current (2020) and Future (2030-2035) Technologies

This study provides a comprehensive life cycle analysis (LCA), or cradle-to-grave (C2G) analysis, of the cost and greenhouse gas (GHG) emissions of a variety of vehicle-fuel pathways, the levelized cost of driving (LCD) and cost of avoided GHG emissions. The C2G analysis assesses light duty midsize sedans and small sport utility vehicles (SUVs) across a variety of vehicle-fuel technology pathways, including conventional internal combustion engine vehicles (ICEVs), flexible hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs) with varying vehicle ranges, and fuel cell electric vehicles (FCEVs). Coming at a timely manner, given the marked increase, since 2016, in climate aspirations announced by governmental institutions and private firms both in the US and across the globe, this analysis builds on a previous comprehensive life cycle analysis, updating that study’s 2016 assumptions and methods (Elgowainy et al. 2016). These updates incorporate technological advances and changes in energy supply sources that have emerged during the intervening period. Utilizing these updated assumptions and methods, alongside more recent data, the present report accounts for a broader range of vehicle technologies and considers both current (2020) and expected future (2030-2035) conditions. Reflecting increased research interest in synthetic liquid fuels produced using renewable low-carbon electricity and CO 2 sources, electro-fuels (a.k.a. e-fuels) were added to the potential future fuel technologies that are evaluated. This study takes a “pathway” approach rather than a “scenario” approach; hence distinct, technically feasible, routes or sequences of processes starting with one or more feedstocks and ending with an intermediate or a final product are examined, not necessarily constrained by practical feedstock, economic, policy, and market considerations.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Effects of knock intensity measurement technique and fuel chemical composition on the research octane number (RON) of FACE gasolines: Part 2 – Effects of spark timing

The Research and Motor Octane Number (RON, MON) characterize a fuel’s knock resistance by rating the knock intensity of a sample fuel relative to that of Primary Reference Fuels (PRF) in a Cooperative Fuel Research (CFR) Engine. A fuel’s octane number is regulated to prevent damage from autoignition leading to knocking combustion in spark-ignition engines. The operational differences between the standard RON rating and modern engine operation are explored in a three-part publication series. The previous study focused on the effects of lambda and knock characterization. This second study primarily focuses on the effects of spark timing on RON determination. Following the findings from the first publication, the knock intensity was captured by the knockmeter and by the maximum amplitude of pressure oscillations (MAPO) at the lambda of peak knock intensity and stoichiometry. Knock-limited spark advance tests were conducted for a set of seven Fuels for Advanced Combustion Engines (FACE) from the Coordinating Research Council (CRC) with varying chemical composition, PRFs, and Toluene Standardization Fuels (TSFs). For retarded spark timings, pre-spark low-temperature heat release was found for low RON PRFs. Low RON PRFs also showed knocking characteristics before reaching the center of combustion suggesting that the use of knock-limited spark advance (KLSA) was preferred over the knock-limited combustion phasing. Primarily paraffinic fuels tended towards increased pressure oscillations while dominantly aromatic fuels experienced higher pressure rise rates. A MAPO-based KLSA correlated best to Octane Index at a negative K-factor suggesting beyond RON operation despite being at otherwise RON conditions. At stoichiometry, the MAPO-based KLSA did neither correlate to RON nor Octane Index. Finally, good agreement was found between KLSA-based effective RON from this study to the MAPO-based effective RON from the first study.

10 SYNTHETIC FUELS↗