Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Life Cycle”

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 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
NASA NTRS2008

Space Transportation Systems Life Cycle Cost Assessment and Control

Civil and military applications of space transportation have been pursued for just over 50 years and there has been, and still is, a need for safe, dependable, affordable, and sustainable space transportation systems. Fully expendable and partially reusable space transportation systems have been developed and put in operation that have not adequately achieved this need. Access to space is technically achievable, but presently very expensive and will remain so until there is a breakthrough in the way we do business. Since 1991 the national Space Propulsion Synergy Team (SPST) has reviewed and assessed the lessons learned from the major U.S. space programs of the past decades focusing on what has been learned from the assessment and control of Life Cycle Cost (LCC) from these systems. This paper presents the results of a selected number of studies and analyses that have been conducted by the SPST addressing the need, as well as the solutions, for improvement in LCC. The major emphasis of the SPST processes is on developing the space transportation system requirements first (up front). These requirements must include both the usual system flight performance requirements and also the system functional requirements, including the infrastructure on Earth's surface, in-space and on the Moon and Mars surfaces to determine LCC. This paper describes the development of specific innovative engineering and management approaches and processes. This includes a focus on flight hardware maturity for reliability, ground operations approaches, and business processes between contractor and government organizations. A major change in program/project cost control is being proposed by the SPST to achieve a sustainable space transportation system LCC - controlling cost as a program metric in addition to the existing practice of controlling performance and weight. Without a firm requirement and methodically structured cost control, it is unlikely that an affordable and sustainable space transportation system LCC will ever be achieved. '

Robinson, John W.↗
DOE OSTI2020

Performance analysis of hybrid power configurations: Impact on primary energy intensity, carbon dioxide emissions, and life cycle costs

In this work, utilization of Natural gas and Hydrogen to support current and future building energy needs to offset the total electric demand while improving the grid resiliency and energy efficiency was investigated. Demand side energy management will play an important role in efficiently managing the available energy resources. Performance assessment of different power generation and energy management configurations is presented in this paper. Development of solutions in addressing grid resiliency by providing the ability to design suitable configurations for meeting individual building energy needs is discussed. Primary movers (PM) such as internal combustion engines (ICE) and fuel cells (FC) along with small scale auxiliary renewable energy source such as photovoltaics (PV) were considered. Key attributes of total carbon foot-print, life cycle costs including capital and operational expenditure, electric grid offset or peak shaving capability, thermal energy availability and its further potential to offset total electric demand, and primary energy intensity are analyzed and discussed in detail.

08 HYDROGEN↗
DOE OSTI2026

Comparative life cycle assessment of bioenergy in Japan from residual biomass-based wood pellets produced in the US Pacific Northwest

The US Pacific Northwest (PNW) faces an increase in wildfires due to forest overcrowding and climate change, posing significant environmental and public health risks. Traditional methods of managing surplus biomass, including prescribed burning, have increased air pollution and global warming. While in the PNW, residual woody biomass is being treated as waste, Japan’s growing demand for bio-based energy presents an opportunity to export value-added biomass as energy pellets. This study investigates whether producing wood pellets from the residual woody biomass from forest operations and sawmills for electricity generation in Japan is truly environmentally beneficial. Accordingly, we conducted a cradle-to-grave Life Cycle Assessment (LCA) to evaluate the environmental impact of residual pellets vs. coal for electricity generation. The assessment covered feedstock production, pellet processing, transportation, and combustion phases. Our findings indicate that replacing coal-based electricity in Japan with PNW residual pellet-based electricity can lower the Global Warming Potential (GWP) by about 90% for every unit of electricity displaced. Furthermore, the results show that repurposing the otherwise burnt harvest slash residues for pellet production would improve local air quality by reducing PM 2.5 and smog in the PNW. However, substituting coal with residual pellets marginally increased carcinogenic and ecotoxicity-related emissions. Based on these results, we conclude that substituting coal with residual wood pellets for electricity generation, particularly harvest-slash residual pellets, is environmentally beneficial across most impact categories, including the GWP. This research underscores how an export‑oriented pellet industry can help address the environmental challenges within the regional US wood products industry and global renewable energy supply.

Velappan, Hemalatha [Univ. of Washington, Seattle,↗
DOE OSTI2021

Process modeling, techno-economic assessment, and life cycle assessment of the electrochemical reduction of CO 2 : a review

The electrochemical reduction of CO 2 has emerged as a promising alternative to traditional fossil-based technologies for the synthesis of chemicals. Its industrial implementation could lead to a reduction in the carbon footprint of chemicals and the mitigation of climate change impacts caused by hard-to-decarbonize industrial applications, among other benefits. However, the current low technology readiness levels of such emerging technologies make it hard to predict their performance at industrial scales. During the past few years, researchers have developed diverse techniques to model and assess the electrochemical reduction of CO 2 toward its industrial implementation. The aim of this literature review is to provide a comprehensive overview of techno-economic and life cycle assessment methods and pave the way for future assessment approaches. First, we identify which modeling approaches have been conducted to extend analysis to the production scale. Next, we explore the metrics used to evaluate such systems, regarding technical, environmental, and economic aspects. Finally, we assess the challenges and research opportunities for the industrial implementation of CO 2 reduction via electrolysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Life cycle of a cyanobacterial carboxysome

Carboxysomes, prototypical bacterial microcompartments (BMCs) found in cyanobacteria, are large (~1 GDa) and essential protein complexes that enhance CO 2 fixation. While carboxysome biogenesis has been elucidated, the activity dynamics, lifetime, and degradation of these structures have not been investigated, owing to the inability of tracking individual BMCs over time in vivo. In this work, we have developed a fluorescence-imaging platform to simultaneously measure carboxysome number, position, and activity over time in a growing cyanobacterial population, allowing individual carboxysomes to be clustered on the basis of activity and spatial dynamics. We have demonstrated both BMC degradation, characterized by abrupt activity loss followed by polar recruitment of the deactivated complex, and a subclass of ultraproductive carboxysomes. Together, our results reveal the BMC life cycle after biogenesis and describe the first method for measuring activity of single BMCs in vivo.

09 BIOMASS FUELS↗
DOE OSTI2024

Techno-economic and life-cycle analysis of strategies for improving operability and biomass quality in catalytic fast pyrolysis of forest residues

Many of the challenges faced by the first commercial biorefineries were associated with feedstock handling, quality, and cost. Strategies are needed to enable further expansion of biorefineries and meet the growing demand for bio-based fuels and products. Here, we examine 2 key feedstock challenges and mitigation strategies in the context of a catalytic fast pyrolysis (CFP) biorefinery: (1) the operability of the feed system, which may be improved by modifying the minimum particle size fed to the reactor, and (2) the quality of the biomass, which may be improved by employing air classification to remove undesirable material and increase fuel yields. We conduct techno-economic analysis (TEA) and life-cycle analysis for these strategies, employing a discrete event simulation model for biomass preprocessing combined with a series of correlations developed from literature data and a rigorous CFP conversion model. Our results highlight the importance of balancing increased cost and material losses from preprocessing against improved operability and fuel yields. Economics and sustainability were optimized when operating at the lowest minimum particle size, emphasizing the importance of minimizing material losses while maintaining the operability of the process. Economically, additional costs and material losses from air classification could be acceptable due to improved biomass conversion, and an optimum air classification speed was identified; however, the fuel GHG emissions were minimized when air classification was not used. Valorizing material removed during preprocessing as a coproduct could improve economics and sustainability, decreasing the burden of material losses.

09 - BIOMASS FUELS↗
DOE OSTI2019

Selenium Nanocomposite Cathode with Long Cycle Life for Rechargeable Lithium‐Selenium Batteries

Abstract Selenium (Se) is a potential cathode material for high energy density rechargeable lithium batteries. In this study, a binder‐free Se‐carbon nanotube (CNT) composite electrode has been prepared by a facile chemical method. At initial state, Se is present in the form of branched nanowires with a diameter of <150 nm and a length of 1–2 μm, interwoven with CNTs. After discharge and re‐charge, the Se nanowires are converted to nanoparticles embedded in the CNT network. This synthesis method provides a path for fabricating the Se cathodes with controllable mass loading and thickness. By studying the composite electrodes with different Se loading and thickness, we found that the electrode thickness has a critical impact on the distribution of Se during repeated cycling. Promising cycling performance was achieved in thin electrodes with high Se loading. The composite electrode with 23 μm thickness and 60 % Se loading shows a high initial capacity of 537 mAh g −1 and stable cycling performance with a capacity of 401 mAh g −1 after 500 cycles at 1 C rate. This study reports a synthesis strategy to obtain Se/CNT composite cathode with long cycle life for rechargeable Li−Se batteries.

Cui, Yi↗
DOE OSTI2019

Conversion of Distiller’s Grains to Renewable Fuels and High Value Protein: Integrated Techno-Economic and Life Cycle Assessment

Distiller’s grains are a byproduct of corn ethanol production and provide an opportunity for increasing the economic viability and sustainability of the overall grain-to-fuels process. Typically, these grains are dried and sold as a ruminant feed adjunct. Here, this study considers utilization of the residuals in a novel supplementary fermentation process to produce two products, enriched protein and fusel alcohols. The value-added proposition and environmental impact of this second fermentation step for distiller’s grains are evaluated by considering three different processing scenarios. Techno-economic results show the minimum protein selling price, assuming fusel alcohol products are valued at 0.79 cents per liter gasoline equivalent, ranges between 1.65–2.48 kg protein –1 for the different cases. Environmental impacts of the systems were evaluated through life cycle assessment. Results show a baseline emission results of 17 g CO 2-eq (MJ fuel) –1 for the fuel product and 10.3 kg CO 2-eq kg protein –1 for the protein product. Sensitivity to allocation methods show a dramatic impact with results ranging between –8 to 140 g CO 2-eq (MJ fuel) –1 for the fuel product and –0.3 to 6.4 kg CO 2-eq kg protein –1 for the protein product. The discussion is focused on the potential impact of the technology on corn ethanol production economics and sustainability.

09 BIOMASS FUELS↗
DOE OSTI2025

Enhancing Cycle Life in Superoxide‐Based Na–O 2 Batteries by Reducing Interface Reactivity

Abstract Sodium–oxygen (Na–O 2 ) batteries are considered a promising energy storage alternative to current state‐of‐the‐art technologies owing to their high theoretical energy density, along with the natural abundance and low price of Na metal. The chemistry of these batteries depends on sodium superoxide (NaO 2 ) or peroxide (Na 2 O 2 ) being formed/decomposed. Most Na–O 2 batteries form NaO 2 , but reversibility is usually quite limited due to side reactions at interfaces. By using new materials, including a highly active catalyst based on vanadium phosphide (VP) nanoparticles, an ether/ionic liquid‐based electrolyte, and an effective sodium bromide (NaBr) anode protection layer, the sources of interface reactivity can be reduced to achieve a Na–O 2 battery cell that is rechargeable for 1070 cycles with a high energy efficiency of more than 83%. Density functional theory calculations, along with experimental characterization confirm the three factors leading to the long cycle life, including the effectiveness of the NaBr protective layer on the anode, a tetraglyme/EMIM‐BF 4 based electrolyte that prevents oxidation of the VP cathode catalyst surface, and the EMIM‐BF 4 ionic liquid aiding in avoiding electrolyte decomposition on NaO 2 .

Azaribeni, Adel [Department of Chemical and Biolog↗
DOE OSTI2024

Ion Exchange Processes for CO 2 Mineralization Using Industrial Waste Streams: Pilot Plant Demonstration and Life Cycle Assessment

Abstract An attractive technique for removing CO 2 from the environment is sequestration within stable carbonate solids (e. g., calcite). However, continuous addition of alkalinity is required to achieve favorable conditions for carbonate precipitation (pH>8) from aqueous streams containing dissolved CO 2 (pH<4.5) and Ca 2+ ions. In this study, a pH‐swing process using ion exchange was demonstrated to process 300 L of produced water brine per day for CO 2 mineralization. Proton titration capacities were quantified for aqueous streams in equilibrium with gas streams at various concentrations of CO 2 (pCO 2 =0.03–0.20 atm) and at various flow rates (0.5–2.0 L min −1 ). Energy intensities for the process were determined to be between 30 and 65 kWh per tonne of CO 2 sequestered depending on the composition of the brine stream. A life cycle assessment was performed to analyze the net carbon emissions of the technology which indicated a net CO 2 reduction for pCO 2 ≥0.12 atm (−0.06–−0.39 kg CO 2 e per kg precipitated CaCO 3 ) utilizing calcium‐rich brines. The results from this study indicate the ion exchange process can be used as a scalable method to provide alkalinity necessary for the capture and storage of CO 2 in Ca‐rich waste streams.

Chemistry↗
DOE OSTI2019

Integrating Data Science Methods and Life Cycle Assessment (LCA): Application to the Power Sector - ISSST2019

This work was presented at the International Symposium on Sustainable Systems and Transportation (ISSST) 2019 Conference in Portland, OR on June 26, 2019. Data science is radically transforming the scientific landscape. Data-intensive frameworks such as LCA can uniquely benefit from the establishment of large-scale and national datasets, and the use of data-science methods. Additionally, the synthesis and application of these data repositories in LCA can aid in improving emissions inventories, technological characterization of product systems, and uncertainty quantification. In this work, a series of case studies are used to explore the intersection of data science and LCA of the power sector. The objective of this work is to provide a broad cross-section of data sources, methods, and approaches that have been applied to characterize the life cycle of power systems, but are generalizable across multiple LCA research domains.

Littlefield, James↗
NASA NTRS2014

The Influence of Free Space Environment in the Mission Life Cycle: Material Selection

The natural space environment has a great influence on the ability of space systems to perform according to mission design specification. Understanding the natural space environment and its influence on space system performance is critical to the concept formulation, design, development, and operation of space systems. Compatibility with the natural space environment is a primary factor in determining the functional lifetime of the space system. Space systems being designed and developed today are growing in complexity. In many instances, the increased complexity also increases its sensitivity to space environmental effects. Sensitivities to the natural space environment can be tempered through appropriate design measures, material selection, ground processing, mitigation strategies, and/or the acceptance of known risks. The design engineer must understand the effects of the natural space environment on the space system and its components. This paper will discuss the influence of the natural space environment in the mission life cycle with a specific focus on the role of material selection.

Edwards, David L.↗
DOE OSTI2026

Ambient-Pressure Chemical Recycling of Thermoset Carbon Fiber-Reinforced Polymers via Low-Temperature Solvolysis: Techno-Economic and Life-Cycle Assessment

Carbon fiber-reinforced polymer (CFRP) waste is rapidly accumulating, with global volumes projected to exceed 500,000 tons annually by 2050. Virgin carbon fiber production is extremely energy- and cost-intensive, and growing demand has intensified supply-chain vulnerabilities associated with precursor availability and reliance on critical materials. Scalable recycling technologies therefore offer not only environmental benefits but also opportunities to reduce material costs and strengthen domestic composite supply chains. This study introduces an efficient, mild chemical recycling method for epoxy-amine CFRPs, utilizing acetic acid (80 wt%) and zinc acetate (1 wt%) at atmospheric pressure and low temperature (~110 °C). The solvolysis process preserves residual resin (~40%) on recycled carbon fibers (rCF), enhancing interfacial bonding in remanufactured composite materials. Recycled fibers retain ~90% of their mechanical properties, and recovered oligomers show potential for reuse in epoxy formulations, supporting material circularity. Techno-economic analysis (TEA) and life-cycle assessment (LCA) confirm the scalability and sustainability of this process.

Recycling CFRP↗
DOE OSTI2022

Rapid growth of anthropogenic organic nanoparticles greatly alters cloud life cycle in the Amazon rainforest

Aerosol-cloud interactions remain uncertain in assessing climate change. While anthropogenic activities produce copious aerosol nanoparticles smaller than 10 nanometers, they are too small to act as efficient cloud condensation nuclei (CCN). The mechanisms responsible for particle growth to CCN-relevant sizes are poorly understood. Here, we present aircraft observations of rapid growth of anthropogenic nanoparticles downwind of an isolated metropolis in the Amazon rainforest. Model analysis reveals that the sustained particle growth to CCN sizes is predominantly caused by particle-phase diffusion-limited partitioning of semivolatile oxidation products of biogenic hydrocarbons. Cloud-resolving numerical simulations show that the enhanced CCN concentrations in the urban plume substantially alter the formation of shallow convective clouds, suppress precipitation, and enhance the transition to deep convective clouds. The proposed nanoparticle growth mechanism, expressly enabled by the abundantly formed semivolatile organics, suggests an appreciable impact of anthropogenic aerosols on cloud life cycle in previously unpolluted forests of the world.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Life-Cycle Assessment of Alternative Pyrolysis-Based Transport Fuels: Implications of Upgrading Technology, Scale, and Hydrogen Requirement

In an effort to diversify liquid fuel supply and address climate change, there are ongoing studies on the use of biomass as a renewable source of energy. Bio-oil produced from fast pyrolysis of biomass is a promising substitute for fossil fuels that can meet climate change mitigation goals, spur rural economies, and diversify liquid fuel supply. However, for bio-oil to be used as a transportation fuel, it requires upgrading to remove oxygen present in the oil. Hydrodeoxygenation (HDO) is one means of upgrading fast pyrolysis oil, however, one of its main limitations is a large hydrogen requirement. We evaluate an alternative electrochemical deoxygenation (EDOx) method that uses catalytic electrode membranes on a ceramic, oxygen permeable support, to generate hydrogen in-situ for deoxygenation at the cathode and remove oxygen at the anode. We analyze the life cycle greenhouse gas (GHG) emissions and scale effects of gas-phase upgrading pyrolysis oil (300 metric tons per day (MTPD)) using EDOx, which reduces energy needs for condensing the pyrolysis gas to bio-oil prior to deoxygenation. The dispersed woody biomass can be accessed and thus more efficiently used if a small scale process is used to densify and stabilize the bio-oil product. We evaluate two configurations of the small-scale deoxygenation, full electrochemical deoxygenation (EDOx), which removes 100% of oxygen present in the bio-oil and partial EDOx, which removes 96% of oxygen present in the bio-oil and compare them to the large scale (2000 MTPD) deoxygenation (HDO). The partial EDOx process has the lowest total GHG emissions of 4.95 gCO2 eq. and 7.43 gCO2 eq. per MJ of a vehicle operated with diesel and gasoline respectively compared to full EDOx (8.36 g CO2 eq. diesel, 10.86 g CO2 eq. gasoline) and HDO (39 gCO2 eq. per MJ for diesel and gasoline). In addition, with the EDOx processes, we can site 10 times more small-scale pyrolysis upgrading sites compared to HDO, suggesting that small-scale on-site partial or full deoxygenation can reach more inaccessible forest biomass resources.

bio-oil hydrotreating, Biomass, deoxygenation, sol↗
DOE OSTI2021

Technoeconomic and Life Cycle Analysis for Bio-Energy with Carbon Capture and Storage (BECCS) Baseline

Bio-Energy with Carbon Capture and Storage (BECCS) is an attractive option from an environmental standpoint, as biomass regrowth removes CO 2 from the atmosphere, which offsets the emissions produced by burning the biomass. When combined with carbon capture, this produces a system that is capable of zero or even negative greenhouse gas (GHG) emissions. This study examines the performance, environmental impact, and economics of co-firing biomass in pulverized coal (PC) power plants. The analysis is based on various plant configurations (with and without carbon dioxide [CO 2 ] capture) using hybrid poplar biomass at three levels of co-fire (20, 35, and 49 weight percent) with Illinois No. 6 coal. This study is an analysis of the overall performance and economics of the plant, which was used to determine the levelized cost of electricity (LCOE) and to perform a full environmental life cycle analysis (LCA) of greenfield PC plants co-firing biomass.

09 BIOMASS FUELS↗
DOE OSTI2016

Concentrated Electrolyte for the Sodium-Oxygen Battery: Solvation Structure and Improved Cycle Life

Alkali metal-oxygen batteries are of great interests for energy storage because of their unparalleled theoretical energy densities. Particularly attractive is the emerging Na-O 2 battery because of the formation of superoxide as the discharge product. Dimethyl sulfoxide (DMSO) is a promising solvent for this battery but its instability towards Na makes it impractical in the Na-O 2 battery. Here in this paper, we report the enhanced stability of Na in DMSO solutions containing concentrated sodium trifluoromethanesulfonimide (NaTFSI) salts (>3molkg -1 ). Raman spectra of NaTFSI/DMSO electrolytes and abinitio molecular dynamics simulation reveal the Na + solvation number in DMSO and the formation of Na(DMSO) 3 (TFSI)-like solvation structure. The majority of DMSO molecules solvating Na + in concentrated solutions reduces the available free DMSO molecules that can react with Na and renders the TFSI anion decomposition, which protects Na from reacting with the electrolyte. Using these concentrated electrolytes, Na-O 2 batteries can be cycled forming sodium superoxide (NaO 2 ) as the sole discharge product with improved long cycle life, highlighting the beneficial role of concentrated electrolytes for Na-based batteries.

25 ENERGY STORAGE↗
DOE OSTI2020

Microanalysis of Primary Biological Particles from Model Grass over Its Life Cycle

Airborne biological aerosols are an integral part of the atmosphere–biosphere interface and significantly impact the environment and Earth’s climate. Primary biological particles such as fungal spores, bacteria, and fragments of plant debris are emitted directly from the biosphere into the atmosphere. The phyllosphere (aboveground plant surfaces) is one of the major habitats for different microbes. Here, atmospheric emissions of primary biological particles from model grass Brachypodium distachyon were monitored by online particle number concentration counting at eight principal growth stages starting from leaf development to senescence. Particles collected at each of the growth stages were then characterized using microspectroscopy techniques. Our findings indicate that the morphological and compositional characteristics of emitted biological particles are highly variable at the different growth stages. We identified fungal spores as the most abundant biological particles in the heading stage, while bacteria were most abundant in the flowering and fruit development stages. Understanding differences in the composition and morphology of biological particles during the plant life cycle provides more accurate and reliable insights on structural, functional, and biochemical properties of plant systems, as well as their interactions with microbial communities. This study also provides insights into Earth geoscience system models that represent primary biological particle emissions from the biosphere.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗