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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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Thermal Stability Analysis of Gevo Jet Fuel Using Ellipsometry

Thermal stability is an important characteristic of alternative fuels that must be evaluated before they can be used in aviation engines. This characteristic is of great importance to the effectiveness of the fuel as a coolant and to the engine's combustion performance. The thermal stability of Gevo fuel, an alcohol to jet fuel made from plant feedstock was studied. This analysis was used to make comments on the effectiveness of the current thermal stability test standard. This work was performed using a spectroscopic ellipsometer to measure the thickness of deposits left on aluminum substrates. It was observed that Gevo deposit thickness increased slowly up to 375 C and much more rapidly after that point. Similar behavior was observed in JP-8 fuel. Comparisons were also made between color standard ratings and ellipsometric thickness measurements, and it was found that in some cases, darker colors did not indicate thicker deposits. Reference tubes were used to validate the optical models used in this work, and different optical constants were found to best model the results than what are published in the ASTM D3241 test method for thermal stability.

Ellipsometry↗
DOE OSTI2021

Biofuels for a sustainable future

Rapid increases of energy consumption and human dependency on fossil fuels have led to the accumulation of greenhouse gases and consequently, climate change. As such, major efforts have been taken to develop, test, and adopt clean renewable fuel alternatives. Production of bioethanol and biodiesel from crops is well developed, while other feedstock resources and processes have also shown high potential to provide efficient and cost-effective alternatives, such as landfill and plastic waste conversion, algal photosynthesis, as well as electrochemical carbon fixation. In addition, the downstream microbial fermentation can be further engineered to not only increase the product yield but also expand the chemical space of biofuels through the rational design and fine-tuning of biosynthetic pathways toward the realization of "designer fuels" and diverse future applications.

09 BIOMASS FUELS↗
DOE OSTI2021

The Transportation Energy and Mobility Pathway Options (TEMPO) Model: Overview and Validation of V1.0 [Slides]

This presentation documents the approaches and methods used in the Transportation Energy & Mobility Pathway Options™ (TEMPO) model to evaluate passenger and freight demand for transportation and mobility services, project vehicle ownership and technology adoption decisions, and determine transport mode choices to derive scenarios of future energy use and emissions. TEMPO is an all-inclusive transportation demand model that covers the entire United States, with an implicit spatial resolution and an hourly temporal resolution that allows for generating time-resolved energy use profiles to assess multisectoral integration aspects. Key features of the TEMPO model include the ability to perform endogenous out-of-sample forecasting to extrapolate recent emerging trends and analyze impacts of disruptive technological breakthroughs and behavioral changes. TEMPO employs an innovative representation of passenger mobility demand stemming from household-level decisions that determine vehicle adoption, ownership, and use based on sociodemographics (e.g., income, household composition), technology attributes (e.g., travel cost, time), geography (e.g., urban, suburban, rural) and population-specific multiday mobility and travel requirements. This representation enables a more forward-looking perspective on the use of new mobility options and the adoption of alternative fuel vehicles, as well as a more accurate representation of their energy usage profiles than previous modeling approaches. A comparison with the U.S. Energy Information Administration’s Annual Energy Outlook showcases the ability of TEMPO to accurately replicate widely accepted projections by representing the key elements of the entire transportation sector at the appropriate level of resolution. TEMPO is intended to generate future scenarios of technology adoption, energy use, and emissions in the transportation sector to compare alternatives, inform decision makers, and assess integration with energy infrastructure and supply systems at an appropriate spatiotemporal resolution.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Clean Cities: A Model of Collaborative Technology Innovation Built Over 30 Years

The Clean Cities Coalition Network is an example of successful government-sponsored efforts to reduce petroleum use and facilitate collaborative governance across sectors and levels of government within the transportation sector. In 1993, under what is now the Vehicle Technologies Office (VTO), the U.S. Department of Energy (DOE) established Clean Cities in response to a requirement in the Energy Policy Act (EPAct) of 1992 to implement voluntary alternative fuel deployment activities. VTO's Technology Integration Program is responsible for the Clean Cities Coalition Network and many other activities. DOE created a collaborative governance effort that has translated higher-level policy goals into multiple local collaborative practices for more than 30 years.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2020

INTERFUEL: EPAct 2005 Section 701 Waiver and Compliance Process [Slides]

This presentation presents an overview of the coming changes to how federal agencies with motor vehicles and which are subject to requirements for alternative fuel use under Energy Policy Act of 2005 Section 701 will request waivers, if needed, from that requirement. The presentations provides an overview of the requirement, how those waivers have been requested in recent history, why the process is changing, and the implications of those changes for relevant federal agencies. The presentation is intended for delivery via WebEx at the June 10, 2020 meeting of the DOE-sponsored INTERFUEL working group.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2023

Analysis of Benefits Associated With Projects and Technologies Supported by the Clean Transportation Program: 2023 Executive Summary [Slides]

In 2007, California Assembly Bills (AB) 118 and 109 created the Clean Transportation Program (CTP), which authorized the California Energy Commission (CEC) to fund projects concerning alternative fuels and advanced transportation technologies to help attain the state's climate change policies. AB 109 also required CEC to prepare a report summarizing the benefits resulting from the program. Since then, CEC has collaborated with National Renewable Energy Laboratory to prepare and publish biannual reports summarizing CTP's benefits related to petroleum displacement, greenhouse gas (GHG) reductions, air pollution, and more. This report updates the input data, calculation methodologies, and resulting outputs from CEC's 2021 report.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2021

Spatial and unobserved heterogeneity in consumer preferences for adoption of electric and hybrid vehicles: A Bayesian hierarchical modeling approach

The transition to low carbon vehicles known as alternative fuel vehicles (AFVs) is well underway. This transition has been motivated partly by consumer demand and partly by legislation such as the Zero Emission Vehicle mandate, which requires manufacturers to sell a certain percentage of their vehicles as AFVs. While the long-term adoption of AFVs (specifically, electric and hybrids) may take several years, there is a need to understand consumer preferences for AFV adoption and the pathways of AFV adoption from a national perspective. Therefore, this study sought to provide information about consumer preferences regarding AFV ownership while considering spatial and unobserved heterogeneity in consumer preferences, which can potentially impact societal transition to low carbon fueled vehicles. The 2017 National Household Travel Survey was used to calibrate Bayesian logit and hierarchical models. Here, the findings of these models reveal that higher gasoline prices contribute toward the adoption of battery electric vehicles. The results also reveal that the perceived disadvantages of AFVs for long commutes are the key barrier in wider adoption of AFVs. Interestingly, frequent use of the internet by consumers revealed a higher likelihood for purchase of hybrid vehicles. Furthermore, West Coast residents are observed to be a large portion of the early adopters and are more likely to purchase hybrids as compared to battery electric vehicles. The knowledge generated by this study has implications for making better informed decisions about AFV adoption and developing incentives to promote wider adoption of AFVs by overcoming their perceived disadvantages.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2023

National Electric Vehicle Infrastructure Formula Program Annual Report: Plan Year 2022-2023

The National Electric Vehicle Infrastructure (NEVI) Formula Program provides nearly $5 billion over 5 years to help states, the District of Columbia, and Puerto Rico (hereafter referred to as “states”) create a network of fast EV charging stations along designated Federal Highway Administration (FHWA) Alternative Fuel Corridors (AFCs), with emphasis along the Interstate Highway System. The first-year deployment plans were submitted to and reviewed by the Joint Office and FHWA and certified by FHWA in September 2022. To support the rollout of the NEVI Formula Program, the Joint Office has been providing technical assistance to the states since February 2022 and has developed DriveElectric.gov to serve as the front door for federal efforts to build out a national charging network. This report summarizes the key activities of the Joint Office in relation to the NEVI program and provides an individual and collective overview of the first-year deployment plans. The Joint Office will utilize the summary of these plans to inform program improvement and future technical assistance activities to support the states as they begin to implement their EV charging infrastructure.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2021

Recent advances in CO 2 hydrogenation to value-added products — Current challenges and future directions

Climate change, global warming, fossil fuel depletion and rising fuel prices have created great incentives to seek alternative fuel production technologies. CO 2 transformation to value-added products using renewable H 2 has proven to be an emerging solution to enable this goal. In this regard, three different promising processes, namely methane, methanol and hydrocarbon synthesis via CO 2 hydrogenation are thoroughly discussed. In addition, the influential factors affecting process efficiencies such as catalyst design and mechanistic insight, operating conditions as well as reactor types are investigated, with key pathways that dictate catalyst activity and selectivity of the most promising materials described. Furthermore, a brief overview of the reactor configuration and its crucial role in the improving process viability is analyzed. Accordingly, fixed-bed, fluidized-bed, annular and spherical reactors along with H 2 O/H 2 perm-selective membrane reactors are disscussed for hydrocarbon production. In addition, different reactor configurations are compared to assess the best one that is adjustable depending on the reaction mechanism. In conclusion, a corrugated-wall dual-type membrane reactor is proposed as an emerging alternative for CO 2 hydrogenation to value-added products.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

SHOCK TUBE IGNITION STUDIES OF RENEWABLE DIESEL FUELS FOR MEDIUM AND HEAVY-DUTY TRANSPORTATION

Currently extensive research on alternative fuels is being conducted due to their increasing demand to reduce greenhouse emissions. One renewable fuel studied in this work is dimethyl ether (DME) blended with propane(C3H8) as a potential mixture for heavy-duty engines used in semi-trucks. The blend has the potential to drastically reduce particulate and greenhouse gas emissions compared to a conventional diesel engine operating under similar conditions. To develop the use of mixture, one must conduct detailed conceptual and simulation studies before progressing to detail studies in CFD, engine modifications, and live testing. For simulations, accurate high-fidelity chemical kinetic models are necessary. However, the validity of the chemical kinetic mechanism for operating conditions of a heavy-duty mixing-controlled compression (MCCI) engine was widely unknown until recent work presented here and published. In this work, we studied the ignition of DME and propane blends in a shock tube under MCCI engine conditions. Ignition delay time (IDT) gathered behind the reflected shock for DME-propane mixtures for heavy-duty compression ignition (CI) engine parameters. Testing was conducted for undiluted varieties spanning from temperatures of 700 to 1100 K at pressures ranging from 55 to 84 bar for various blends (100% CH3OCH3, 100% C3H8, 60% CH3OCH3/ 40% C3H8) of DME and propane were combusted in synthetic air (21% O2/ 79% N2). Several experiments were conducted at higher pressures (90-120 bar) to improve the model performance and accuracy. The ignition delay times (IDTs) were compared to recent mechanisms, including Aramco3.0, NUIG, and Dames et al. A common trend among the mechanisms was overpredicted experimental IDTs. Further studies were conducted by a sensitivity analysis using the Dames et al. model, and critical reactions sensitive to IDTs of DME-propane mixture near 60 bar are outlined. Chemical analysis was conducted on the NTC region to explain chemical kinetics which is critical for developing MCCI heavy duty engines.

Mohammed, Zuhayr Pasha↗
NASA NTRS1975

Fuel-conservative engine technology

Aircraft fuel consumption is discussed in terms of its efficient use, and the conversion of energy from sources other than petroleum. Topics discussed include: fuel from coal and oil shale, hydrogen deficiency of alternate sources, alternate fuels evaluation program, and future engines.

Dugan, J. F., Jr.↗
NASA NTRS1980

Rating hydrogen as a potential aviation fuel

The viability of liquid hydrogen, liquid methane, and synthetic aviation kerosene as future alternate fuels for transport aircraft is analyzed, and the results of a comparative assessment are given in terms of cost, energy resource utilization, areas of fuel production, transmission airport facilities, and ultimate use in the aircraft. Important safety (fires) and some environmental aspects (CO2 balance) are also described. It is concluded that fuel price estimates indicate the price of synthetic aviation kerosene (synjet) would be approximately half of the price calculated for liquid hydrogen and somewhat less than that of liquid methane, with synjet from oil shale reported to be the least expensive.

Witcofski, R. D.↗
NASA NTRS1998

Emissions Measurements from a Lobed Fuel Injector/Burner

The present experimental study examines NO(x) and CO emissions associated with alternative fuel injector geometries. These injectors mix fuel and air to differing extents and thus create different local equivalence ratios upstream of flame ignition and stabilization. Two of the devices studied are lobed fuel injectors, in which mixing of reactants is associated with stream wise vorticity generation and straining of fuel-air interfaces, while the third is a non-lobed fuel injector which creates relatively little fuel-air mixing prior to ignition.Results show that one lobed injector geometry appears to produce locally lean premixed flame structures, resulting in low NO. emissions when compared with non-lobed injector emissions. The other lobed injector geometry appears to produce a local fuel-air mixture which is closer to stoichiometric conditions, with NO(x) emissions that are actually higher than for the non-lobed injector. For both lobed injector geometries examined here, CO emissions become high for over-all lean operating conditions, consistent with premixed combustion behavior. The present study demonstrates the importance of control of the local equivalence ratio in minimizing burner emissions.

Mitchell, M. G.↗
NASA NTRS2011

Fischer-Tropsch Catalyst for Aviation Fuel Production

As the oil supply declines, there is a greater need for cleaner alternative fuels. There will undoubtedly be a shift from crude oil to non-petroleum sources as a feedstock for aviation (and other transportation) fuels. The Fischer-Tropsch process uses a gas mixture of carbon monoxide and hydrogen which is converted into various liquid hydrocarbons; this versatile gas-to-liquid technology produces a complex product stream of paraffins, olefins, and oxygenated compounds such as alcohols and aldehydes. The Fischer-Tropsch process can produce a cleaner diesel oil fraction with a high cetane number (typically above 70) without any sulfur and aromatic compounds. It is most commonly catalyzed by cobalt supported on alumina, silica, or titania or unsupported alloyed iron powders. Cobalt is typically used more often than iron, in that cobalt is a longer-active catalyst, has lower water-gas shift activity, and lower yield of modified products. Promoters are valuable in improving Fischer-Tropsch catalyst as they can increase cobalt oxide dispersion, enhance the reduction of cobalt oxide to the active metal phase, stabilize a high metal surface area, and improve mechanical properties. Our goal is to build up the specificity of the Fischer-Tropsch catalyst while adding less-costly transition metals as promoters; the more common promoters used in Fischer-Tropsch synthesis are rhenium, platinum, and ruthenium. In this report we will describe our preliminary efforts to design and produce catalyst materials to achieve our goal of preferentially producing C8 to C18 paraffin compounds in the NASA Glenn Research Center Gas-To-Liquid processing plant. Efforts at NASA Glenn Research Center for producing green fuels using non-petroleum feedstocks support both the Sub-sonic Fixed Wing program of Fundamental Aeronautics and the In Situ Resource Utilization program of the Exploration Technology Development and Demonstration program.

deLaRee, Ana B.↗
NASA NTRS2012

Fischer-Tropsch Catalyst for Aviation Fuel Production

As the oil supply declines, there is a greater need for cleaner alternative fuels. There will undoubtedly be a shift from crude oil to nonpetroleum sources as a feedstock for aviation (and other transportation) fuels. The Fischer-Tropsch process uses a gas mixture of carbon monoxide and hydrogen which is converted into various liquid hydrocarbons; this versatile gas-to-liquid technology produces a complex product stream of paraffins, olefins, and oxygenated compounds such as alcohols and aldehydes. The Fischer-Tropsch process can produce a cleaner diesel oil fraction with a high cetane number (typically above 70) without any sulfur and aromatic compounds. It is most commonly catalyzed by cobalt supported on alumina, silica, or titania or unsupported alloyed iron powders. Cobalt is typically used more often than iron, in that cobalt is a longer-active catalyst, has lower water-gas shift activity, and lower yield of modified products. Promoters are valuable in improving Fischer-Tropsch catalyst as they can increase cobalt oxide dispersion, enhance the reduction of cobalt oxide to the active metal phase, stabilize a high metal surface area, and improve mechanical properties. Our goal is to build up the specificity of the Fischer-Tropsch catalyst while adding less-costly transition metals as promoters; the more common promoters used in Fischer-Tropsch synthesis are rhenium, platinum, and ruthenium. In this report we will describe our preliminary efforts to design and produce catalyst materials to achieve our goal of preferentially producing C8 to C18 paraffin compounds in the NASA Glenn Research Center Gas-To-Liquid processing plant. Efforts at NASA Glenn Research Center for producing green fuels using non-petroleum feedstocks support both the Sub-sonic Fixed Wing program of Fundamental Aeronautics and the In Situ Resource Utilization program of the Exploration Technology Development and Demonstration program.

DeLaRee, Ana B.↗
NASA NTRS1978

Future directions in aeronautical research and technology

The aeronautical R & D effort in NASA is discussed with emphasis on those areas where major needs and opportunities exist. In aerodynamics, areas selected for discussion include computational aerodynamics, transonic test techniques, high Reynolds number research, skin friction drag reduction, and propulsive lift. In propulsion, consideration is given to the areas of fuel-efficient subsonic propulsion, variable-flow engines, hypersonic propulsion, alternate fuels, and aircraft noise reduction. Consideration is also given to the utilization of advanced composites and integrated avionic systems.

Bower, R. E.↗
NASA NTRSDate not supplied

TPSAS-NF1676L-18116-DND

Generational improvement in transport aircraft led to aggressive reductions in noise, emissions, and fuel burn. Technological advances needed across many fronts (aerodynamics, propulsion, alternative fuels, acoustics, structures). Broad structures-centric goals (for wings): stabilize flexibility in minimum-weight wings; and exploit flexibility to reduce wing loading/drag via load redistribution and wing shaping.

Bret K Stanford↗