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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Electrolyte Engineering for Efficient Electrochemical Nitrate Reduction to Ammonia on a Titanium Electrode

Nitrates from agricultural runoff and industrial waste streams are a notorious waste product and hazardous pollutant. Traditional electrochemical water remediation approaches aim to solve this problem by converting nitrates to environmentally benign N 2 while minimizing the production of environmentally hazardous side products such as ammonia and nitrous oxide in a process known as “denitrification”. We modify this concept and outline an opportunity to optimize the conversion of nitrates into ammonia, which is also a key commodity product used as a fertilizer, potential fuel, and chemical precursor. The electrochemical conversion of nitrates to ammonia recycles the fixed nitrogen and offers an appealing and supplementary alternative to the energy- and resource-intensive Haber-Bosch process. In this study, we investigated the effect of varying electrochemical conditions (pH, nitrate concentration, and applied potential) on the selective reduction of nitrate to ammonia at a titanium cathode. We observed that high concentrations of both protons and nitrate ions are needed to achieve high selectivity, reaching a peak of 82% Faradaic efficiency to ammonia at an applied potential of -1 V versus RHE and a partial current density to NH 3 of -22 mA/cm 2 , using 0.4 M [NO 3 – ] at pH ~0.77. The Ti electrode, as a poor hydrogen evolution catalyst with notable corrosion resistance, provides a large window of operating conditions to achieve high selectivity in the reduction of nitrate anions. Stability of the system was evaluated, and we found a high Faradaic efficiency throughout the course of an 8 h experiment. After electrochemical testing, titanium hydride was observed at the cathode surface. We also show a preliminary technoeconomic study, indicating that it may be feasible to employ an electrochemical strategy for the production of ammonium nitrate.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1979

Improved coal-slurry pipeline

High strength steel pipeline carries hot mixture of powdered coal and coal derived oil to electric-power-generating station. Slurry is processed along way to remove sulfur, ash, and nitrogen and to recycle part of oil. System eliminates hazards and limitations associated with anticipated coal/water-slurry pipelines.

Dowler, W. L.↗
DOE OSTI2023

A multifunctional copper single-atom electrocatalyst aerogel for smart sensing and producing ammonia from nitrate

Despite modern chemistry’s success in providing affordable fertilizers for feeding the population and supporting the ammonia industry, ineffective nitrogen management has led to pollution of water resources and air, contributing to climate change. Here, we report a multifunctional copper single-atom electrocatalyst-based aerogel (Cu SAA) that integrates the multiscale structure of coordinated single-atomic sites and 3D channel frameworks. The Cu SAA demonstrates an impressive faradaic efficiency of 87% for NH 3 synthesis, as well as remarkable sensing performance with detection limits of 0.15 ppm for NO 3 − and 1.19 ppm for NH 4 + . These multifunctional features enable precise control and conversion of nitrate to ammonia in the catalytic process, facilitating accurate regulation of the ammonium and nitrate ratios in fertilizers. We thus designed the Cu SAA into a smart and sustainable fertilizing system (SSFS), a prototype device for on-site automatic recycling of nutrients with precisely controlled nitrate/ammonium concentrations. The SSFS represents a forward step toward sustainable nutrient/waste recycling, thus permitting efficient nitrogen utilization of crops and mitigating pollutant emissions. This contribution exemplifies how electrocatalysis and nanotechnology can be potentially leveraged to enable sustainable agriculture.

Science & Technology - Other Topics↗
DOE OSTI2022

EDGE2D-EIRENE and ERO2.0 predictions of nitrogen molecular break-up and transport in the divertor of JET low-confinement mode plasmas

EDGE2D-EIRENE simulations of nitrogen-seeded partially detached JET L-mode plasmas show that the divertor N I to N V radiation distributions are highly sensitive to the upstream electron density, and less sensitive to changes in the assumed cross-field particle diffusivity for nitrogen ions. The EDGE2D-EIRENE simulations reproduce the peak intensities of N I to N V as measured by vertically viewing divertor filterscopes to within 50 % for a narrow range of the upstream electron density within the experimental uncertainties, while the predicted profiles are narrower than the measured ones. Including nitrogen atoms only in the ERO2.0 simulations implies lower N III and N IV peak intensities by one and two thirds, respectively, compared to EDGE2D-EIRENE. If nitrogen is assumed to recycle exclusively as molecules instead of atoms, ERO2.0 predicts that the N III and N IV intensities in the divertor increase by up to a factor of two and that the time-averaged, volume-integrated number of N 5+ to N 7+ ions in the plasma also increases by approximately a factor of 2.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1992

Technology development for lunar base water recycling

This paper will review previous and ongoing work in aerospace water recycling and identify research activities required to support development of a lunar base. The development of a water recycle system for use in the life support systems envisioned for a lunar base will require considerable research work. A review of previous work on aerospace water recycle systems indicates that more efficient physical and chemical processes are needed to reduce expendable and power requirements. Development work on biological processes that can be applied to microgravity and lunar environments also needs to be initiated. Biological processes are inherently more efficient than physical and chemical processes and may be used to minimize resupply and waste disposal requirements. Processes for recovering and recycling nutrients such as nitrogen, phosphorus, and sulfur also need to be developed to support plant growth units. The development of efficient water quality monitors to be used for process control and environmental monitoring also needs to be initiated.

Schultz, John R.↗
NASA NTRS1996

A bioreactor system for the nitrogen loop in a Controlled Ecological Life Support System

As space missions become longer in duration, the need to recycle waste into useful compounds rises dramatically. This problem can be addressed by the development of Controlled Ecological Life Support Systems (CELSS) (i.e., Engineered Closed/Controlled Eco-Systems (ECCES)), consisting of human and plant modules. One of the waste streams leaving the human module is urine. In addition to the reclamation of water from urine, recovery of the nitrogen is important because it is an essential nutrient for the plant module. A 3-step biological process for the recycling of nitrogenous waste (urea) is proposed. A packed-bed bioreactor system for this purpose was modeled, and the issues of reaction step segregation, reactor type and volume, support particle size, and pressure drop were addressed. Based on minimization of volume, a bioreactor system consisting of a plug flow immobilized urease reactor, a completely mixed flow immobilized cell reactor to convert ammonia to nitrite, and a plug flow immobilized cell reactor to produce nitrate from nitrite is recommended. It is apparent that this 3-step bioprocess meets the requirements for space applications.

NASA Discipline Number 61-10↗
NASA NTRS1997

Mechanism and potential applications of bio-ligninolytic systems in a CELSS

A large amount of inedible plant material, generated as a result of plant growth in a Controlled Ecological Life Support System (CELSS), should be pretreated and converted into forms that can be recycled on earth as well as in space. The main portion of the inedible biomass is lignocellulosic material. Enzymatic hydrolysis of this cellulose would provide sugars for many other uses by recycling carbon, hydrogen, oxygen, and nitrogen through formation of carbon dioxide, heat, and sugars, which are potential foodstuffs. To obtain monosaccharides from cellulose, the protective effect of lignin should be removed. White-rot fungi degrade lignin more extensively and rapidly than other microorganisms. Pleurotus ostreatus degrades lignin effectively, and produces edible and flavorful mushrooms that increase the quality and nutritional value of the diet. This mushroom is also capable of metabolizing hemicellulose, thereby providing a food use of this pentose containing polysaccharide. This study presents the current knowledge of physiology and biochemistry of primary and secondary metabolisms of basidiomycetes, and degradation mechanism of lignin. A better understanding of the ligninolytic activity of white-rot fungi will impact the CELSS Program by providing insights on how edible fungi might be used to recycle the inedible portions of the crops.

Review↗
NASA NTRS1994

Evolution of the martian atmosphere

Carbon dioxide, nitrogen, and the nonradiogenic and radiogenic noble gases are tracked from primordial inventories to their present states in a revised model of atmospheric evolution on Mars. Elemental and isotopic abundances evolve by hydrodynamic escape, impact erosion, outgassing, sputtering, photochemical escape of nitrogen, and carbonate formation and recycling. Atmospheric history is divided into early and late evolutionary periods, the first characterized by high CO2 pressures and a possible greenhouse and the second by a low pressure cap-regolith buffered system initiated by polar CO2 condensation approximately 3.7 Gyr ago. During early evolution the Xe isotopes are fractionated to their present composition by hydraulic escape, and CO2 pressure and isotopic history are dictated by the interplay of losses to erosion, sputtering, and carbonate precipitation, additions by outgassing and carbonate recycling, and perhaps also by feedback stabilization under greenhouse conditions. Atmospheric collapse near 3.7 Gyr leads to abrupt increases in the mixing ratios of preexisting Ar, Ne, and N2 at the exobase and their rapid removal by sputtering. Current abundances and isotopic compositions of these light species are therefore entirely determined by the action of sputtering and photochemical escape on gases supplied by outgassing during the late evolutionary epoch. The present atmospheric Kr inventory also derives almost completely from solar-like Kr degassed during this period. Consequently, among current observables, only the Xe isotopes and delta(C-13) survive as isotopic tracers of atmospheric history prior to its transition to low pressure.

Pepin, Robert O.↗
NASA NTRS2001

Turning Gas into Greens

Scientists from Cook College, Rutgers University, and Stevens Institute of Technology conducted studies to create an experimental greenhouse that uses methane from decomposing trash to fuel a system that makes food. Biogasses created by the anaerobically decomposing trash are necessary to fulfill the energy needs of this revolutionary greenhouse. The primary emission, methane, is piped to the greenhouse boiler and used to fuel the hot water heating system. Thus far, the use of biogas has drastically reduced the operating costs of the greenhouse, eliminating the need for non-renewable fuels. The biogas will also generate electricity for the greenhouse in the near future. The plants are irrigated with recycled plant nutrients such as nitrogen, phosphorus, potassium, calcium, and magnesium. These nutrients are delivered through hydroponics, the cultivation of plants in a nutrient solution rather than in soil. High-pressure sodium lamps augment the natural light, thereby boosting production and reducing cropping time. A total of 16 hours of light are provided to the crop each day, year-round. It only takes about 90 days for a seed to germinate and produce a tomato harvest. Not only is the food produced faster, the manual labor needed for the upkeep of the plants is also drastically reduced.

Source record↗
DOE OSTI2021

Design and operational considerations of catalytic membrane reactors for ammonia synthesis

Production of ammonia using hydrogen derived from renewable electricity instead of hydrocarbon reforming would dramatically reduce the carbon footprint of this commodity chemical. Novel technologies such as catalytic membrane reactors may potentially be more compatible with distributed ammonia production than the conventional Haber-Bosch process. Here, a reactor model is developed based on integrating a standard industrial iron catalyst into a catalytic membrane reactor (CMR) equipped with an inorganic membrane that is selective to NH 3 over N 2 /H 2 . CMR performance is studied as functions of wide ranges of membrane properties and operating conditions. Conversion and ammonia recovery are dictated principally by the ammonia permeance, and the benefits by using membranes become significant above 100 GPU = 3.4 × 10 –8 mol m –2 s –1 Pa –1 . To be effective, the CMR requires a minimum selectivity for ammonia of 10 over both nitrogen and hydrogen, and purity scales with the effective selectivity. Increasing the pressure of operation significantly improves all metrics, and at P = 30 bar with a quality membrane ammonia is almost completely recovered, enabling direct recycle of un-reacted hydrogen and nitrogen without need for recompression. Temperature drives conversion and scales monotonically without thermodynamic limitations in a CMR. Alternatively, the temperature may be reduced as low as 300°C while achieving conversion levels surpassing equilibrium limits at T = 400°C in a conventional reactor.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Bacterial Community Assembly, Succession, and Metabolic Function during Outdoor Cultivation of Microchloropsis salina

Outdoor cultivation of microalgae has promising potential for renewable bioenergy, but there is a knowledge gap on the structure and function of the algal microbiome that coinhabits these ecosystems. Here, we describe the assembly mechanisms, taxonomic structure, and metabolic potential of bacteria associated with Microchloropsis salina cultivated outdoors. Open mesocosms were inoculated with algal cultures that were either free of bacteria or coincubated with one of two different strains of alga-associated bacteria and were sampled across five time points taken over multiple harvesting rounds of a 40-day experiment. Using quantitative analyses of metagenome-assembled genomes (MAGs), we tracked bacterial community compositional abundance and taxon-specific functional capacity involved in algal-bacterial interactions. One of the inoculated bacteria (Alteromonas sp.) persisted and dispersed across mesocosms, whereas the other inoculated strain (Phaeobacter gallaeciensis) disappeared by day 17 while a taxonomically similar but functionally distinct Phaeobacter strain became established. The inoculated strains were less abundant than 6 numerically dominant newly recruited taxa with functional capacities for mutualistic or saprophytic lifestyles, suggesting a generalist approach to persistence. This includes a highly abundant unclassified Rhodobacteraceae species that fluctuated between 25% and 77% of the total community. Overall, we did not find evidence for priority effects exerted by the distinct inoculum conditions; all mesocosms converged with similar microbial community compositions by the end of the experiment. Instead, we infer that the 15 total populations were retained due to host selection, as they showed high metabolic potential for algal-bacterial interactions such as recycling alga-produced carbon and nitrogen and production of vitamins and secondary metabolites associated with algal growth and senescence, including B vitamins, tropodithietic acid, and roseobacticides.

rhodobacteraceae↗
NASA NTRS1995

Evaluations of an Enhanced Total Hydrocarbon Analyzer With Complex Mixtures of Volatile Organic Compounds

From the earliest manned missions, the volatile organic compound (VOC) content of spacecraft air has been a concern because of a much greater potential for contamination than air in most terrestrial settings. First, the volume of air is small compared to the mass of man- made materials comprising the interior furnishings of the spacecraft. These man-made materials offgas VOCs trapped during manufacture. Second, the nitrogen fraction of the air is recycled. Any VOCs not scrubbed out with charcoal filters or aqueous condensate (mainly water expired by the crew) will accumulate in the air. Third, the crew emits metabolic VOCs. Fourth, experimental payloads can also offgas or accidentally release a VOC; in fact a major organic constituent of the atmosphere is the disinfectant isopropanol released from swabs used in medical experiments.

Cross, John H.↗
DOE OSTI2023

Stable ammonia absorbents

The present disclosure relates to systems and methods of making ammonia using stable ammonia absorbents. The system and method for producing ammonia, comprises a reactor comprising a catalyst that converts at least a portion of nitrogen feed gas and at least a portion of hydrogen feed gas to ammonia (NH3) forming a reaction mixture comprising the ammonia, unreacted nitrogen, and unreacted hydrogen. An absorber configured to selectively absorb ammonia from the reaction mixture at a temperature of about 180 deg. C. to 330 deg. C. and a pressure of about 1-20 bar, the absorber comprising a solid absorbent. Preferably the solid absorbent is at least one metal halide and a solid support. The unabsorbed ammonium, the unreacted nitrogen, and unreacted hydrogen gas are recycled to the reactor.

Cussler, Edward↗
DOE OSTI2022

Integrated flux and pool size analysis in plant central metabolism reveals unique roles of glycine and serine during photorespiration

Photorespiration is an essential process juxtaposed between plant carbon and nitrogen metabolism that responds to dynamic environments. Photorespiration recycles inhibitory intermediates arising from oxygenation reactions catalysed by Rubisco back into the C 3 cycle, but it is unclear what proportions of its nitrogen-containing intermediates (glycine and serine) are exported into other metabolisms in vivo and how these pool sizes affect net CO 2 gas exchange during photorespiratory transients. Here, to address this uncertainty, we measured rates of amino acid export from photorespiration using isotopically non-stationary metabolic flux analysis. This analysis revealed that ~23–41% of the photorespiratory carbon was exported from the pathway as serine under various photorespiratory conditions. Furthermore, we determined that the build-up and relaxation of glycine pools constrained a large portion of photosynthetic acclimation during photorespiratory transients. Furthermore, these results reveal the unique and important roles of glycine and serine in successfully maintaining various photorespiratory fluxes that occur under environmental fluctuations in nature and providing carbon and nitrogen for metabolism.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS2012

Organic Geochemistry of the Hamersley Province: Relationships Among Organic Carbon Isotopes, Molecular Fossils, and Lithology

Molecular fossils are particularly valuable ancient biosignatures that can provide key insight about microbial sources and ecology in early Earth studies. In particular, hopanes carrying 2-methyl or 3-methyl substituents are proposed to be derived from cyanobacteria and oxygen-respiring methanotrophs, respectively, based on both their modem occurrences and their Proterozoic and Phanerozoic sedimentary distributions. Steranes are likely from ancestral eukaryotes. The distribution of methylhopanes, steranes, and other biomarkers in 2.72-2.56 billion-year-old rocks from the Hamersley Province, Western Australia show relationships to lithology, facies, and isotopes of macromolecular carbon, and other biomarkers. These observations support biomarker syngenicity and thermal maturity. Moreover, ecological signatures are revealed, including a surprising relationship between isotopic values for bulk macromolecular carbon and the biomarker for methanotrophs. The record suggests that cyanobacteria were likely key organisms of shallow-water microbial ecosystems providing molecular oxygen, fixed carbon, and possibly fixed nitrogen, and methanotrophs were not alone in recycling methane and other C-13-depleted substrates.

Eigenbrode, Jennifer L.↗
DOE OSTI2023

Combined Algal Processing for the Synthesis of Liquid Oleofuels and Products (CAPSLOC) - WBS 1.3.4.204

Combined Algal Processing for the Synthesis of Liquid Oleofuels and Products (CAPSLOC) aims to develop a biorefinery concept that is composition-agnostic and enables economically, environmentally, and socially viable biofuel production by maximizing the value from each fraction. To achieve this, we have employed an iterative approach between R&D and TEA/LCA to establish process targets and quantify improvements in the minimum fuel selling price (MFSP), reduce carbon intensity, and support the state of technology (SOT). We have surveyed various methods for biomass pretreatment and successfully demonstrated pre-pilot scale pretreatment in batch mode. Using techniques such as lipid modification, fermentation, mild oxidative treatment (MOT), and carbonization, we have developed biofuel precursors and a range of value-added co-products. Our project has demonstrated significant improvements in key aspects of algae processing, particularly in pretreatment technologies suitable for variable composition, co-products available from lipid and extracted solid streams, conditioning and fermenting high-protein hydrolysates, and recovering nitrogen (N) and phosphorus (P) nutrients for recycling to cultivation ponds. The success of this project will support the commercialization of a sustainable microalgal biorefinery industry.

biofuel↗
DOE OSTI2023

Mechanisms behind impurity spreading in a channeled, long-leg divertor configuration

One suggested benefit of long-leg, tightly baffled divertor configurations, a common feature included in the designs of many next-generation fusion devices, is access to a delocalized “spread” of impurity radiation along the leg, allowing for a substantial radiation region while maintaining both sufficient distance from the core to prevent pollution of the plasma fuel and avoiding local overheating of the plasma-facing materials. However, it is unclear whether this increased connection length and divertor volume afforded by the long-leg configuration is compatible with impurity transport, and whether it will enable this desired impurity radiation spread at all. Here, the SOLPS 4.3 code is used to assess the distribution of nitrogen and neon impurity radiation in a long-leg, tightly baffled divertor geometry. Further, there is a strong correspondence between the distribution of impurity radiation in the long leg and impurity recycling on the divertor side walls with both the nitrogen simulation set and the neon simulation set, suggesting that impurity spreading along these long legs is due to the interplay between the cross-field transport and associated neutralization of the impurity on the material surfaces.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗