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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

FCIC DFO--Moisture Management and Optimization in Municipal Solid Waste Feedstock through Mechanical Processing

The project goal is to produce densified product, focusing on characteristics of bulk density, durability, and moisture content, to reduce the cost of preprocessing. The objective of the project is to efficiently manage and handle the properties of MSW feedstock through INL-developed fractional milling, high moisture pelleting, and low temperature drying preprocessing technologies .

09 BIOMASS FUELS↗
DOE OSTI2025

Impact of Storage Conditions on the Quality and Viability of Switchgrass as a Bioenergy Crop

With growing energy demands and climate concerns, advancements in bioenergy have become imperative. Biofuels promote energy independence, reduce fossil fuel reliance, and cut greenhouse gas emissions. Switchgrass (Panicum virgatumis) is an ideal bioenergy crop due to its ability to thrive on marginal lands unsuitable for food crops and its drought tolerance, rendering it a low-maintenance, high-yield option. In the bioenergy industry, energy crops are typically stored to facilitate supply chain management and ensure a continuous supply despite seasonal availability. However, the effective utilization of bioenergy crops is typically contingent upon addressing the challenges associated with biomass storage. These challenges include high moisture content that promotes biological degradation of the biomass leading to increased risk of pathogenic microbes, and chemical degradation that increases the ratio of inconvertible, inorganic materials. These issues lead to a reduction of feedstock value, diminishing the biomass-to-biofuel conversion efficacy, making switchgrass and other bioenergy crops less effective as fuel sources. This project aims to improve the storage of purpose-grown energy crops. Aerobic storage trials were conducted under varying moisture contents to stimulate real-world environmental exposure. Switchgrass samples were rewetted to 30% or 35% and stored in a bioreactor for approximately one month, or until cellular respiration ceased. Degradation indicators, such as dry matter loss, temperature changes, and cellular respiration, were measured throughout this process. Samples for compositional analysis, 16S, and ITS were taken at three different time points: before, during, and after storage, to monitor changes in biomass, microbial communities, and metabolites over time. Preliminary data indicate that dry matter loss is proportional to cellular respiration, with higher moisture content (35%) leading to higher temperatures and elevated dry matter loss. Compositional analysis and microbial community analysis are in progress. This research will provide a comprehensive understanding of storage, helping to identify stability factors in energy crops and improve best management practices for biomass producers.

09 - BIOMASS FUELS↗
DOE OSTI2023

Modeling the Impact of the Organic Aerosol Phase State on Multiphase OH Reactive Uptake Kinetics and the Resultant Heterogeneous Oxidation Timescale of Organic Aerosol in the Amazon Rainforest

Accurate predictions of chemical lifetime, i.e., oxidation timescale and change in the mass of organic aerosols (OAs) in atmospheric models, are critical to quantify the impacts of OA on aerosol–cloud interactions, radiative forcing, and air quality. The heterogeneous oxidation of OA by hydroxyl (OH) radicals is a key process governing OA mass changes during their oxidation. Recently, laboratory observations of the OH uptake coefficient (γ OH ) and heterogeneous reaction rate (k het,OH ) for different OA systems with varying phase states have been combined to develop a new parameterization of γ OH and k het,OH as a function of the OA phase state, i.e., viscosity (η OA ). Here, in this work, we use a recently published viscosity prediction framework to analyze the new γ OH and k het,OH parameterization with a box model. Subsequently, we implement this box model to predict γ OH and k het,OH over the Amazon rainforest in the dry-to-wet transition season with both significant biomass burning and biogenic influences. Relevant parameters within our box model are specified based on detailed regional model simulations over the Amazon using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). η OA is predicted as a function of species volatility, OA composition (including water uptake) along with ambient relative humidity (RH), and temperature. Based on ambient conditions simulated by WRF-Chem over the entire atmospheric column, we use the box model to predict the upper bounds of the heterogeneous oxidation timescale of OA. Based on previous laboratory measurements, we assume that this heterogeneous OH oxidation causes fragmentation (carbon loss) of OA, followed by the evaporation of the fragmented molecules that results in the exponential decay of OA. We predict that the oxidation timescale of OA is ~1 month near the Earth’s surface in the pristine Amazonian background because of low OH concentrations. But OA is oxidized more rapidly within urban and wildfire plumes near the Earth’s surface with an order of magnitude higher OH concentrations compared to the pristine background, causing the simulated oxidation timescale of OA to be much shorter, ~3–4 days. At 3–5 km altitudes where biomass burning OA is predicted to be semisolid, the heterogeneous oxidation timescale is estimated as ~6 days to 3 weeks and decreases with increasing OH concentrations within plumes. We show that the simulated mass loss of OA is strongly size-dependent, where smaller particles oxidize more rapidly compared to larger particles due to their greater per-particle surface area-to-volume ratio. Increasing urbanization and deforestation in the Amazon in the future might increase OH concentrations in the background Amazon, causing faster oxidation of OA. At higher altitudes above liquid clouds, especially in the upper troposphere where temperatures approach ~250 K, future measurements are needed to reduce the uncertainties related to the mass loss of OA at colder temperatures and low relative humidity conditions due to its heterogeneous OH oxidation.

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

Five-year yield and physiology data for Populus deltoides grown in South Carolina

A 6-year study in Sumter Co., SC, to determine crown and leaf attributes, supplemental water and fertilization effects on dry weight productivity, and clonal variation accounts in biomass traits. Eight commercially available clones -- ‘ST148’, ‘S2C20’, ‘3167’, ‘ST72’ ‘20WV’, ‘S7C1’, ‘ST70’, and ‘S7C15’, were studied. Drip irrigation rates were used to maintain soil tension of 33 kPa at 15% volumetric soil moisture or 1500 kPa at 10%. Application of macro- and micronutrients occurred via drip irrigation at a high and low rate. The high rate included an initial application of 85 kg elemental nitrogen ha-1, which increased to 182 kg ha-1 at age 3, which then was reduced to 135 kg ha-1 for remainder of the study. The low treatment received 50% (w/v) of the high treatment. Individual tree measurements across time are provided in this dataset.

Populus deltoides, Drip irrigation, N fertigation,↗
DOE OSTI2025

Seasonal investigation of ultrafine-particle organic composition in an eastern Amazonian rainforest

Abstract. Reports on the composition of ultrafine particles (<100 nm in diameter) in the Amazon are scarce, due in part to the fact that new-particle formation has rarely been observed near ground level. Ultrafine particles near the surface have nevertheless been observed, leaving open questions regarding the sources and chemistry of their formation and growth, particularly as these vary across seasons. Here, we present measurements of the composition of ultrafine particles collected in the Tapajós National Forest (2.857° S, 54.959° W) during three different seasonal periods: 10–30 September 2016 (SEP), 18 November–23 December 2016 (DEC), and 22 May–21 June 2017 (JUN). Size-selected (5–70 nm) particles were collected daily (for 22 h each day) using an offline sampler. Samples collected during the three time periods were compiled and analyzed using liquid chromatography coupled with Orbitrap high-resolution mass spectrometry. Our findings suggest a sustained influence of isoprene organosulfate chemistry on ultrafine particles from the different periods. We present chemical evidence that indicates that biological-spore fragmentation impacted ultrafine-particle composition during the late wet season (JUN), while chemical markers for biomass burning and secondary chemistry peaked during the dry season (SEP and DEC). Higher oxidation states and degrees of unsaturation were observed for organics in the dry season (SEP and DEC), suggesting greater extents of aerosol aging. Finally, applying a volatility parameterization to the observed compounds suggests that organic sulfur species are likely key drivers of new-particle growth in the region due to their low volatility compared to other species.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2011

Atmospheric Chemistry Over Southern Africa

During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semi-permanent atmosphere gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s, and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite-derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field campaigns such as Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE-A), Southern African Fire-Atmosphere Research Initiative (SAFARI-92), and Southern African Regional Science Initiative (SAFARI 2000). Since those large international efforts, satellites have matured enough to enable quantifiable measurements of regional land surface, atmosphere, and ocean. In addition, global and chemical transport models have also been advanced to incorporate various data. Thus, the timing of the workshop was right for a full-fledged re-assessment of the chemistry, physics, and socio-economical impacts caused by pollution in the region, including a characterization of sources, deposition, and feedbacks with climate change.

Gatebe, Charles K.↗
DOE OSTI2022

Simulation of the effects of biomass burning in a mesoscale convective system in the central amazon

During the dry season of 2014, the formation of a mesoscale convective system (MCS) caused intense precipitation and strong winds in the central Amazon region. In this period, cases of MCS that occurred during the days when there were higher concentrations of CO were analyzed. Through this criterion, a case of MCS occurred on August 16th, 2014 was selected. We used the chemical-atmospheric model WRF-Chem to assess the influence of biomass burning aerosol on the intensity of precipitation, winds, vertical and horizontal transport associated with this convective system. We show that biomass burning aerosol reduces the strength of the mesoscale convective system, with less vertical and horizontal transport of carbon monoxide and ozone. Here, in the absence of biomass burning aerosol downdrafts and precipitation rate are more intense, and cloud development up to 5km is more developed, making the horizontal flow and vertical transport of ozone more intense, however, much more efficient in reducing the concentrations of other gases.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2004

Transport of Biomass Burning Emissions from Southern Africa

The transport of biomass burning emissions from southern Africa to the neighboring Atlantic and Indian Oceans during the dry season (May-October) of 2000 is characterized using ground, ozonesonde, and aircraft measurements of carbon monoxide (CO) and ozone (O3) in and around southern Africa, together with the GEOS-CHEM global model of tropospheric chemistry. The model shows a positive bias of approximately 20% for CO and a negative bias of approximately 10-25% for O3 at oceanic sites downwind of fire emissions. Near areas of active fire emissions the model shows a negative bias of approximately 60% and approximately 30% for CO and O3, respectively, likely due to the coarse spatial (2 deg. x 2.5 deg.) and temporal (monthly) resolution of the model compared to that of active fires. On average, from 1994 to 2000, approximately 60 Tg of carbon monoxide (CO) from biomass burning in southern Africa was transported eastward to the Indian Ocean across the latitude band 0 deg. -60 S during the 6 months of the dry season. Over the same time period, approximately 40 Tg of CO from southern African biomass burning was transported westward to the Atlantic Ocean over the latitudes 0 deg. -20 S during the 6-month dry season, but most of that amount was transported back eastward over higher latitudes to the south (21 deg. -60 S). Eastward transport of biomass burning emissions from southern Africa enhances CO concentrations by approximately 4- 13 ppbv per month over the southern subtropical Indian Ocean during the dry season, with peak enhancements in September. Carbon monoxide from southern African and South American biomass burning is seen in the model simulations as far away as Australia, contributing approximately 8 ppbv and approximately 12-15 ppbv CO, respectively, and thus explaining the approximately 20- 25 ppbv observed enhancement of CO over Melbourne in mid-September 2000.

Sinha, Parikhit↗
DOE OSTI2022

Deforestation-induced climate change reduces carbon storage in remaining tropical forests

Abstract Biophysical effects from deforestation have the potential to amplify carbon losses but are often neglected in carbon accounting systems. Here we use both Earth system model simulations and satellite–derived estimates of aboveground biomass to assess losses of vegetation carbon caused by the influence of tropical deforestation on regional climate across different continents. In the Amazon, warming and drying arising from deforestation result in an additional 5.1 ± 3.7% loss of aboveground biomass. Biophysical effects also amplify carbon losses in the Congo (3.8 ± 2.5%) but do not lead to significant additional carbon losses in tropical Asia due to its high levels of annual mean precipitation. These findings indicate that tropical forests may be undervalued in carbon accounting systems that neglect climate feedbacks from surface biophysical changes and that the positive carbon–climate feedback from deforestation-driven climate change is higher than the feedback originating from fossil fuel emissions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Go with the Flow: Additives to Improve the Flowability of Crumbled Corn Stover

For this work, magnesium stearate (MgSt), a common flow additive and anticaking agent, was applied to corn stover feedstocks with three particle sizes. The material handling properties of dry, 15%, and 30% moisture content corn stover were measured with a Freeman FT-4 powder rheometer and mass flow hopper calculations. While hydrated biomass typically exhibits poor flowability, introducing MgSt led to a significant increase in flowability for dry and 15% moisture content feedstocks, with less impact at 30% moisture content. Inverse gas chromatography showed a decrease, up to 40%, in the surface energy of MgSt-coated corn stover. While MgSt may not be ideal for biofuel or chemical production, this study highlights the potential of flow additives to reduce adhesive and cohesive forces, improving biomass feedstock handling.

09 BIOMASS FUELS↗
DOE OSTI2021

Intensified Soil Moisture Extremes Decrease Soil Organic Carbon Decomposition: A Mechanistic Modeling Analysis

Earth system models have predicted that there will be more frequent and severe precipitation and drought events in terrestrial ecosystems. Microbially mediated decomposition of soil organic carbon (SOC) tends to increase as soils wet and decrease as soils dry. However, the long-term SOC change under intensified moisture extremes remains poorly known as it depends on the frequency and intensity of soil drying and wetting. In this study, we explored long-term SOC dynamics under scenarios of alternating drying-wetting cycles using the Microbial-ENzyme Decomposition model, a mechanistic microbial model. The model was parameterized with 11 years of observations from a temperate deciduous broadleaf forest site, showing satisfactory model performance in both model calibration (R 2 = 0.67) and validation (R 2 = 0.69) against heterotrophic respiration. We then used the model to simulate the long-term SOC dynamics under five scenarios of alternating drying-wetting cycles with different frequencies and severities over a period of 100 years. Results showed that the changes in active microbial biomass C and the corresponding turnover rates of SOC pools were more sensitive to soil drying than soil wetting. As a result, the cumulative soil carbon emission from microbial respiration decreased by 433.7 g C m -2 after the 100-year simulation in the highest frequency and intensity moisture scenario, but was not significantly affected by the lowest frequency and intensity scenario. This study emphasizes the nonlinear response of SOC decomposition to soil moisture changes, which causes decreased decomposition by microbes under drying that is, not compensated by increased decomposition under wetting conditions.

58 GEOSCIENCES↗
DOE OSTI2020

Techno-Economic Analysis and Global Warming Potential of a Novel Offshore Macroalgae Biorefinery

The success of a large scale macroalgae-based biorefinery is dependent on the demonstration of favorable system economics and environmental sustainability. This study uses detailed process modeling to quantify the mass and energy flows through the various unit operations required for a novel free-floating macroalgae biorefinery concept. The modular process model served as the foundation for the techno-economic and global warming potential analyses used to quantify the sustainability of the proposed concept. This work includes detailed techno-economic results for a complete macroalgae cultivation and conversion system with multiple hatchery configurations and several emerging technologies. System optimization was achieved through the evaluation of various technology options for each unit operation. Technologies considered include traditional twine and textile substrate hatchery configurations, drone assisted seeding and biomass transport, mechanized line seeding and harvesting, adhesive spore mixtures that simplify seeding operations and improve hatchery energetics, and hydrothermal liquefaction to produce upgradable biocrude. Outputs from the system include renewable diesel (R100), naphtha, biochar, nitrogen and phosphorus fertilizers, and aqueous/solid waste streams. Three different system pathways were explored, yielding a biomass production cost ranging from $210 to $565 per dry metric ton and a minimum fuel selling price from $1.35 to $2.91 per liter of gasoline equivalent. Stochastic manipulation of the process model and sensitivity analyses support these results. The global warming potential analysis shows net greenhouse gas emissions ranging from 14 to 29 gCO2-eq MJ-1, supported by stochastic and sensitivity analyses. The recommendations from this work highlight critical areas for research and development investment such that a sustainable macroalgae cultivation and conversion system can be realized.

NOMAD seaweed cultivation, techno-economic analysi↗
DOE OSTI2020

Impacts of Degradation on Water, Energy, and Carbon Cycling of the Amazon Tropical Forests

Selective logging, fragmentation, and understory fires directly degrade forest structure and composition. However, studies addressing the effects of forest degradation on carbon, water, and energy cycles are scarce. Here, we integrate field observations and high-resolution remote sensing from airborne lidar to provide realistic initial conditions to the Ecosystem Demography Model (ED-2.2) and investigate how disturbances from forest degradation affect gross primary production (GPP), evapotranspiration (ET), and sensible heat flux (H). We used forest structural information retrieved from airborne lidar samples (13,500 ha) and calibrated with 817 inventory plots (0.25 ha) across precipitation and degradation gradients in the eastern Amazon as initial conditions to ED-2.2 model. Our results show that the magnitude and seasonality of fluxes were modulated by changes in forest structure caused by degradation. During the dry season and under typical conditions, severely degraded forests (biomass loss ≥66%) experienced water stress with declines in ET (up to 34%) and GPP (up to 35%) and increases of H (up to 43%) and daily mean ground temperatures (up to 6.5°C) relative to intact forests. In contrast, the relative impact of forest degradation on energy, water, and carbon cycles markedly diminishes under extreme, multiyear droughts, as a consequence of severe stress experienced by intact forests. Our results highlight that the water and energy cycles in the Amazon are driven by not only climate and deforestation but also the past disturbance and changes of forest structure from degradation, suggesting a much broader influence of human land use activities on the tropical ecosystems.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Altering plant carbon allocation to stems has distinct effects on rhizosphere soil microbiome assembly, interactions, and potential functions in sorghum

Abstract Altering plant carbon allocation from leaves to stems is key to improve biomass for forage, fuel, and renewable chemicals. The sorghum dry stalk ( D ) locus controls a quantitative trait for sugar accumulation, with enhanced carbon allocation in the stems of juicy green ( dd ) sorghum but reduced carbon allocation in that of dry white ( DD ) sorghum. However, it remains unclear whether altering sorghum sugar accumulation in stem affects below‐ground microbiome. Here we investigated sorghum rhizosphere soil microbiome in near isogenic lines with different magnitude of carbon allocations and accumulation in the stems. Results showed that enhanced carbon accumulation in stems of juicy green sorghum results in stronger selection in rhizosphere microbiome assembly. The rhizosphere soil microbial communities selected in juicy green sorghum tended to be fast‐growing microbial taxa which possessed potential functions that would promote higher potential capacity to use chemically labile carbon sources and potentially result in higher potential decomposition rates. We found the rhizosphere microbes selected by juicy green sorghum form weaker interactions than dry white sorghum. This is the first comprehensive study revealing how the different magnitude of carbon allocations to stems regulates microbial community assembly, microbial interaction, and microbial functions. This study indicates that future plant modification for bioenergy crops should also consider the impacts on belowground microbial community without compromising the sustainability.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1988

The Amazon Boundary Layer Experiment (ABLE 2A) - Dry season 1985

The Amazon Boundary Layer Experiment (ABLE 2A) used data from aircraft, ground-based, and satellite platforms to characterize the chemistry and dynamics of the lower atmosphere over the Amazon Basin during the early-to-middle dry season, July and August 1985. This paper reports the conceptual framework and experimental approach used in ABLE 2A and serves as an introduction to the detailed papers which follow in this issue. The results of ABLE 2A demonstrate that isoprene, methane, carbon dioxide, nitric oxide, dimethylsulfide, and organic aerosol emissions from soils and vegetation play a major role in determining the chemical composition of the atmospheric mixed layer over undisturbed forest and wetland environments. As the dry season progresses, emissions from both local and distant biomass burning become an important source of carbon monoxide, nitric oxide and ozone in the atmosphere over the central Amazon Basin.

Harriss, R. C.↗
NASA NTRS1992

Distribution of tropospheric ozone at Brazzaville, Congo, determined from ozonesonde measurements

An analysis of 33 ozonesonde launches in Brazzaville, Congo (4 deg S, 15 deg E), between June 1990 and May 1991 is presented. The data indicate highest tropospheric amounts between June and early October, coincident with the dry season and with the presence of enhanced widespread biomass burning. The seasonal cycle of ozone derived from the ozonesonde measurements is in good agreement with the climatological seasonal cycle inferred from the use of satellite data amd both seasonal cycles peak in September. Averaged throughout the year, the integrated amount of ozone derived from the ozonesondes is 44 Dobson units (DU) and is 39 DU using the satellite data. Within the troposphere the highest partial pressures are generally found at pressure levels near 700 mbar (about 3 km). Using simultaneous ozonesonde data from Ascension Island (8 deg S, 15 deg W), examples are presented illustrating that differences in the troposphere are primarily responsible for the observed spatial gradients of total ozone observed by TOMS.

Cros, Bernard↗
NASA NTRS2020

Impacts of Degradation on Water, Energy, and Carbon Cycling of the Amazon Tropical Forests

Selective logging, fragmentation, and understory fires directly degrade forest structure and composition. However, studies addressing the effects of forest degradation on carbon, water, and energy cycles are scarce. Here, we integrate field observations and high‐resolution remote sensing from airborne lidar to provide realistic initial conditions to the Ecosystem Demography Model (ED‐2.2) and investigate how disturbances from forest degradation affect gross primary production (GPP), evapotranspiration (ET), and sensible heat flux (H). We used forest structural information retrieved from airborne lidar samples (13,500 ha) and calibrated with 817 inventory plots (0.25 ha) across precipitation and degradation gradients in the eastern Amazon as initial conditions to ED‐2.2 model. Our results show that the magnitude and seasonality of fluxes were modulated by changes in forest structure caused by degradation. During the dry season and under typical conditions, severely degraded forests (biomass loss ≥66%) experienced water stress with declines in ET (up to 34%) and GPP (up to 35%) and increases of H (up to 43%) and daily mean ground temperatures (up to 6.5°C) relative to intact forests. In contrast, the relative impact of forest degradation on energy, water, and carbon cycles markedly diminishes under extreme, multiyear droughts, as a consequence of severe stress experienced by intact forests. Our results highlight that the water and energy cycles in the Amazon are driven by not only climate and deforestation but also the past disturbance and changes of forest structure from degradation, suggesting a much broader influence of human land use activities on the tropical ecosystems.

Marcos Longo↗