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Publications are listed covering NASA research from 1966 to 1973. Several major works covering chloroplast reactions, aerobic green algae and hydrogenease, production of molecular hydrogen, and hydrogen and nitrogen metabolism in purple bacteria are summarized.
Optical measurements of thermospheric and ionospheric processes and their interpretation are reviewed and the chemical reactions and their effects on emissions are discussed. Also included are the phenomena which excite the airglow and aurora, i.e., the solar UV/EUV flux and auroral particle precipitation. Consideration is given to solar flux, atomic emissions, molecular emissions, hydrogen geocorona, and molecular oxygen and the green line nightglow.
Choline chloride-based deep eutectic solvents (DESs) have gained widespread recognition as green solvents in catalysis and separation science as their designer properties permit solvation properties to be modulated by the choice of the hydrogen bond donor (HBD) as well as its molar ratio. Despite being one of the most popular classes of DESs, very little is currently understood regarding how their solvation characteristics differ among themselves as well as from other classes of DESs. Previous studies have shown that the catalytic activity, extraction efficiency, and solubilities of natural compounds can be influenced by the type of choline salt and HBD, but no study has systematically related these parameters with its solvation properties. In this study, inverse gas chromatography was employed for the first time to study the individual solvation characteristics of a diverse range of choline chloride and acetate-based DESs composed of amides, diols, organic acids, and carbohydrates. Furthermore, hydrogen bond acidity was found to be a dominant interaction for all DESs, especially those composed of organic acid HBDs. DESs composed of isomers of butane diol and hexane diol as HBDs exhibited higher hydrogen bond basicity and dispersive-type interactions compared to those composed of urea, acetamide, and organic acids with the position of the hydroxyl functional group influencing their solvation interactions. Choline acetate-based DESs exhibited lower dipolarity and stronger hydrogen bond basicity and dispersive-type interactions compared to choline chloride DESs. The solvation models developed in this study were used to interpret and explain DES behavior in previously reported studies involving catalysis, organic synthesis, and extractions demonstrating that the measured solute–solvent interactions can serve to predict the performance of choline chloride-based DESs when used in various applications.
Though hydrogen is a promising energy carrier for a green future, many challenges persist. One is the difficulty in engineering storage solutions, with metal hydrides being a leading contender among solid-state strategies. To facilitate efficient searching of candidate materials, ridge regression, simple decision trees, random forest ensembles, and gradient boosting ensembles were employed to predict the energy of formation, with the random forest ensemble resulting in the lowest test set error. First, two public databases, Materials Project and HydPark, were searched for metal hydrides. Feature engineering was performed before the models were developed, resulting in electronegativity, density, atomic density, d-character, f-character, band gap, hydrogen weight fraction, magnetization, temperature, and pressure being retained. The models were then benchmarked by the lowest test error before a random forest ensemble was used to populate entries missing energy of formation. Furthermore, all were then scored by hydrogen storage capacity and energy of formation suitability. Readily available features including several derived from only the chemical formula which were found to be highly predictive. and so are promising for high-throughput screening of arbitrary novel hydride formulations and blends for thermodynamic feasibility.
The Fire, Explosion, Compatibility and Safety Hazards of Hydrogen Peroxide NASA technical manual was developed at the NASA Johnson Space Center White Sands Test Facility. NASA Technical Memorandum TM-2004-213151 covers topics concerning high concentration hydrogen peroxide including fire and explosion hazards, material and fluid reactivity, materials selection information, personnel and environmental hazards, physical and chemical properties, analytical spectroscopy, specifications, analytical methods, and material compatibility data. A summary of hydrogen peroxide-related accidents, incidents, dose calls, mishaps and lessons learned is included. The manual draws from art extensive literature base and includes recent applicable regulatory compliance documentation. The manual may be obtained by United States government agencies from NASA Johnson Space Center and used as a reference source for hazards and safe handling of hydrogen peroxide.
Four-carbon olefins, such as 1-butene and 1,3-butadiene, are important chemical feedstocks for the production of adhesives and synthetic rubber. These compounds are found in the C 4 fraction of “green oil” products that can arise during the hydrogenation of acetylene. Here, we demonstrate that control of the catalyst structure increases the yield and productivity of these important olefins with a family of catalyst materials comprising Cu nanoparticles (CuNPs) bound within the pores of Zr-based metal–organic frameworks. Using carbon monoxide as a probe molecule, we characterize the surfaces of these catalytic CuNPs with diffuse reflectance infrared Fourier transform spectroscopy, revealing that the electronic structure of the CuNP surfaces is size-dependent. Furthermore, we find that as the CuNP diameter decreases, the selectivity for C 4 products increases and that lowering the stoichiometric ratio of H 2 /acetylene improves the selectivity and productivity of the catalyst.
The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen and hydrogen rocket engines in the Core Stage (CS). The SLS Core Stage went through Green Run hot-fire testing at NASA Stennis Space Center’s B-2 test facility in 2021. The main goal of this testing was to confirm Core Stage tanking, propulsion and thrust vector control systems operations and performance to verify with predicted models. Two hot-fire (HF) test sequences were performed with the first one (HF1) in January for a test duration of 70 seconds and the second (HF2) testing completed in March for a test duration of 500 seconds. This paper focuses on the base heating anomalies observed during HF1 and HF2 where an extensive fire was observed along the Core Stage base heat shield during test operations. This environment was not anticipated and led to extensive unplanned damage to the thermal protection system which was augmented for flight. Green Run observations also led to a reassessment of flight environments for Artemis I. This paper discusses the potential cause of the anomalies, the flow physics, the reconstructed base environments, and mitigation plans for HF2 and flight.
The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen and hydrogen rocket engines in the Core Stage (CS). The SLS Core Stage went through Green Run hotfire testing at NASA Stennis Space Center’s B-2 test facility in 2021. The main goal of this testing was to confirm Core Stage tanking, propulsion and thrust vector control systems operations and performance to verify with predicted models. Two hot-fire (HF) test sequences were performed with the first one (HF1) in January for a test duration of 70 seconds and the second (HF2) testing completed in March for a test duration of 500 seconds. This paper focuses on the base heating anomalies observed during HF1 and HF2 where an extensive fire was observed along the Core Stage base heat shield during test operations. This environment was not anticipated and led to extensive unplanned damage to the thermal protection system which was augmented for flight. Green Run observations also led to a reassessment of flight environments for Artemis I. This paper discusses the potential cause of the anomalies, the flow physics, the reconstructed base environments, and mitigation plans for HF2 and flight.
Abstract Industrial hydrogenation is a pivotal process in chemical synthesis. However, it has significant drawbacks, including high cost, safety risks associated with the use of molecular hydrogen gas, and substantial energy demands due to the need for elevated temperatures and pressures to achieve satisfactory yields. The borrowing hydrogen synthesis, which enables the transfer of hydrogen between molecules, offers a promising approach for green, one‐pot synthesis of industrially important chemicals and intermediates. Despite its potential, the broad application remains limited due to the reliance on toxic solvents, expensive noble metal catalysts, and the still restricted efficiency and substrate scope. In this study, the first solvent‐free strategy for theN‐alkylation of amines with alcohols is presented, employing an N‐doped graphene‐supported Fe single‐atom catalyst (Fe SA @N‐G; 1.06 wt.%). This approach achieves superior conversion and selectivity (up to 99%) along with record values for turnover number (TON, 1032.7) and turnover frequency (TOF, 413.1 h -1 ) for the coupling reaction of aniline with benzyl alcohol, surpassing all previously reported catalysts. DFT calculations, combined with experimental data, elucidated the reaction mechanism and identified the Fe 1 (III)‐N 4 active site participating in Fe‐H hydride transfer and containing two pyrrolic and two pyridinic nitrogens bound to the Fe center. The developed technology is further supported by the catalyst's excellent scalability, reusability, and performance under continuous‐flow conditions. Additionally, the exceptional efficiency of the single‐atom catalyst is demonstrated across more than 50 substrates, including reactions involving both aliphatic and aromatic amines with aliphatic and aromatic alcohols. The industrial applicability of this technology is validated through the synthesis of pharmaceutically relevant compounds, including stimulant drugs, antihistamines, and pharmaceutical intermediates.
The commercial product resulting from this R&D project will enable cost-effective synthesis of the Carbon Neutral Liquid Fuel (CNLF) ammonia, a common chemical, at a small scale for energy and industrial applications using only intermittent renewable energy, water, and air as feedstocks. These products are also capable of producing electrical energy from the CNLF in a fuel cell mode of operation. Thus, the eventual commercial product enables both single direction production of either CLNF or electricity, or alternatively functions as a fully reversible, self-contained energy storage device. The renewed interest in developing electrolysis systems is driven, in part, by the burgeoning renewable, solar, and wind industries and the need for an energy conversion and storage technology that can convert intermittent solar and wind energy into the production of hydrogen. Electrolysis systems integrated into both distributed and central renewable power plants would utilize solar and wind energy as their primary power source to produce renewably generated hydrogen for local energy storage or chemical feedstock purposes. Ammonia is an excellent surrogate for hydrogen transportation. NH3 presents an attractive alternative to hydrogen as a working fluid in reversible devices towards a sustainable green energy-oriented future. Ammonia can be easily liquefied at room temperature at about 8 bar or at -33°C at ambient pressure. In contrast, the liquefaction temperature of hydrogen is -253°C at ambient pressure. NH3 has a significantly higher volumetric energy density (12.7 MJ/L) than compressed hydrogen (4.5 MJ/L at ~70 MPa) or liquefied hydrogen (8.5 MJ/L). Additionally, ammonia is a widely used raw material for agriculture fertilizer and thus has well-established storage, transport, and handling processes (about 180 million tons of ammonia are produced annually). Techno-economic analysis suggests ammonia is the least expensive fuel among hydrogen, gasoline, natural gas, liquefied petroleum gas, and methanol.
Synthetic fuels (synfuels) are hydrocarbon fuels that source energy from electricity. Synfuels have the potential to significantly reduce greenhouse gas emissions throughout the transportation sector. To achieve this substantial reduction in greenhouse gas emissions, the electricity must be sourced from zero- or near-zero-carbon fuel sources such as solar, wind, hydroelectricity, and nuclear power. Synfuels are produced from a combination of carbon and hydrogen sources. Hydrogen can be sourced from water electrolysis with near-zero-carbon electricity and heat (e.g., nuclear), while carbon dioxide can be sourced from ethanol and ammonia plants. In the hydrocarbon fuel synthesis process, hydrogen and carbon dioxide can be reacted to produce carbon monoxide and water, via the so-called reverse watergas shift reaction. Carbon monoxide can then react with additional hydrogen to form hydrocarbons, with carbon chains ranging from C1–C30 in the reaction known as the Fischer-Tropsch (F-T) synthesis reaction. The synthesized hydrocarbon molecules can then be hydro-processed with additional hydrogen and distilled into different carbon chain lengths so as to be compatible with existing conventional gasoline, jet, and diesel fuels. Carbon-free synfuel production comes with a “green premium” over the manufacture of identical products via conventional fossil fuels. Reports from Argonne National Laboratory (ANL) reveal that hydrogen costs dominate the cost of carbon-free synfuel production. This suggests that for the cost of green synfuel to approach that of conventional petroleum fuel, the cost of hydrogen must be approximately $\$1$/kg. Of the primary low-carbon energy sources, only nuclear carries the potential to produce hydrogen at below $\$2$/kg. (Still a bit above the lofty $\$1$/kg goal, but perhaps manageable). To further identify the potential for creating low-cost synfuels capable of competing with legacy technologies, the Department of Energy Office of Nuclear Energy has funded a multi-program, multi-lab effort among ANL, Idaho National Laboratory (INL), the Integrated Energy Systems (IES) program, and the Light Water Reactor Sustainability (LWRS) program. This collaboration effort will determine the possibility of using current and next generation nuclear reactors to create low-cost carbon-free synfuels for sale in the U.S. energy and commodities market.
Video system combines images from visible spectrum and from three bands in infrared spectrum to produce color-coded display in which hydrogen fires distinguished from other sources of heat. Includes linear array of 64 discrete lead selenide mid-infrared detectors operating at room temperature. Images overlaid on black and white image of same scene from standard commercial video camera. In final image, hydrogen fires appear red; carbon-based fires, blue; and other hot objects, mainly green and combinations of green and red. Where no thermal source present, image remains in black and white. System enables high degree of discrimination between hydrogen flames and other thermal emitters.
Monopropellant propulsion that provides high performance and low hazards compared to state-of-art hydrazine are being investigated under NASA, DOD and commercially sponsored green propellant research and development programs. This NASAeffort looks at phosphate stabilized 50% hydrogen peroxide/water –ethanol blends to evaluate their stability and combustion behavior in submillimeter diameter microtube combustion apparatus for cubesat propulsion applications. Exploratory 7-day stabilitytests find no pressure rise in a sealed test tube environment at room temperature indicating at least short term stability of the mixture. Temperature rise during combustion testing in resistively heated nickel microtube apparatus shows that micro-combustion is achieved in the tube. Propellant density is approximately 1.2 g/cm3compared to 1.0 g/cm3for hydrazine. Theoretical specific impulse of the stoichiometric blend is 219 s at a chamber pressure of 20 psia and an area ratio of 30:1. Density-specific impulseof this blendis263 swhile hydrazine is only about 215-220 sin small reaction control system thrusters. This provides about 20-22% more density-specific impulse for the cubesat compared to hydrazine. The theoreticalcombustion temperature is2168°F, whichis thermally compatible with stainless steel materials of constructionand the nickel catalystused in the tests. Combustion test results are given for stoichiometric, as well as fuel-leanand fuel-richpropellant formulations. Thesetests focus on thermally and catalytically supported combustionin the microtube, whichrequires a microtube preheat temperature of about 900°F and sufficient residence time to achieve combustion that is stable and anchored in the tubewithout blowing through the tube unreacted. Thrust class is expected to be in the 10 mN range based on flow rate and estimated specific impulse.Power requirements are generally below 25 Wto heat the tube. Steady state combustion testing is typically conducted for 3 minutes and shows littledegradation of the hardware over multiple test cyclesindicating thatthere is little catalyst degradation over time and littlecatalyst deactivation due tothe phosphate stabilizer inthe hydrogen peroxide.
Hydrogen production via water electrolysis is a promising and evolving technology. The solid oxide electrolysis cell (SOEC) is one of the several technologies for this purpose. They are alternatives to the traditional hydrogen production from fossil fuels to enhance global energy decarbonization. However, in the bid for sustainability and a green economy, these technologies are not free from causing some environmental burdens. Using life cycle assessment (LCA), the greenhouse gas emission and degree of environmental impacts by these technologies can be identified and measured throughout their lifespan. This study addresses how to quantify these CO 2 emission impacts for an electrolytic system with different energy sources. The LCA of a novel integrated hydrogen production SOEC system with energy from solar photovoltaic and bituminous powerplant is performed using simaPro, the leading global LCA solution software. Measuring the environmental impact of the electrolytic operation in terms of weight, the bituminous powerplant poses damage which is, on average 700% more than solar PV. The thermal-to-hydrogen efficiency of the SOEC system is 56%, and a probable 28% reduction in carbon footprint with heat integration. The steam generation and the manufacturing of the SOEC have a very high environmental impact potential on the system. Here, we recommend LCA and net energy analysis is carried out for every new hydrogen technology and adequate comparison to enhance sustainable and green economy.
As a green solvent for biomass processing, deep eutectic solvents (DESs) have shown effectiveness in biomass processing. Here, in this study, phenolic aldehydes with different numbers of methoxy groups, including 4-hydroxybenzaldehyde (HBA, no methoxy), vanillin (VA, monomethoxy), and syringaldehyde (SA, dimethoxy) were employed to synthesize DESs with choline chloride (ChCl). The presence of methoxy groups in the hydrogen bond donor structure affected DES properties, as well as biomass pretreatment performance. The high thermal stability of phenolic aldehyde DESs was shown with over 225 °C onset temperature. The hydrogen bond donor with one aldehyde and one hydroxyl group at the para position without a methoxy group (ChCl-HBA) showed the highest xylan removal and delignification, reaching 59.3 and 88.0%, respectively, leading to the highest enzymatic hydrolysis yield. Sonication after pretreatment further enhanced the hydrolysis yields, achieving 83.3% glucan conversion and 50.1% xylan conversion. In the lignin-rich fraction, the recovered lignin showed a low weight–average molecular weight under 2100 g/mol with a relatively uniform molecular weight dispersity below 1.5. This study provides insights into how the chemical structure of hydrogen bond donors in DESs affects biomass processing and paves the way for designing effective lignin-derived DES in future biorefinery processes.
Monopropellant propulsion that provides high performance and low hazards compared to state-of-art hydrazine are being investigated under NASA, DOD and commercially sponsored green propellant research and development programs. This NASA effort looks at phosphate stabilized 50% hydrogen peroxide/water –ethanol blends to evaluate their stability and combustion behavior in submillimeter diameter microtube combustion apparatus for cubesat propulsion applications. Exploratory 7-day stability tests find no pressure rise in a sealed test tube environment at room temperature indicating at least short term stability of the mixture. Temperature rise during combustion testing in resistively heated nickel microtube apparatus shows that micro-combustion is achieved in the tube. Propellant density is approximately 1.2 g/cu.cm compared to 1.0 g/cu.cm for hydrazine. Theoretical specific impulse of the stoichiometric blend is 219 s at a chamber pressure of 20 psia and an area ratio of 30:1. Density-specific impulse of this blend is 263 s while hydrazine is only about 215-220 s in small reaction control system thrusters. This provides about 20-22% more density-specific impulse for the cube sat compared to hydrazine. The the oretical combustion temperature is 2168°F, which is thermally compatible with stainless steel materials of construction and the nickel catalyst used in the tests. Combustion test results are given for stoichiometric, as well as fuel-lean and fuel-rich propellant formulations. These tests focus on thermally and catalytically supported combustion in the microtube, which requires a microtube preheat temperature of about 900°F and sufficient residence time to achieve combustion that is stable and anchored in the tube without blowing through the tube unreacted. Thrust class is expected to be in the 10 m N range based on flow rate and estimated specific impulse. Power requirements are generally below 25 W to heat the tube. Steady state combustion testing is typically conducted for 3 minutes and shows little degradation of the hardware over multiple test cycles indicating that there is little catalyst degradation over time and little catalyst deactivation due to the phosphate stabilizer in the hydrogen peroxide.
Microfibrillated lignocellulose networks, derived from agricultural byproducts, represent an environmentally friendly biogenic material production due to their abundant availability to circular bioeconomy and inherent carbon sink in life cycle analysis. Yet, its vulnerability to moisture and flammability, coupled with challenges in creating highly reinforced insulation materials, poses challenges for the carbon-zero green building sector. Here we address these challenges with a new concept of in-situ grafting polymerization of nanoporous silica in pre-formed lignocellulosic fiber networks. The seamlessly integrating nanoporous silica with cellulose through hydrogen bonding networks enabled us to prepare highly reinforced biogenic composites for green building insulations. A high reinforcement biocomposite with hierarchal arrangements of nanoporous silica within the cellulose network exhibits remarkable attributes. It boasts a thermal conductivity of 24.2 mW·m –1 ·K –1 , a flexural modulus of 942 MPa, and soundproofing with a 20.8 % noise reduction, as well as the fire resistance characterized by an extended time to ignition and a reduced peak heat release rate of 144 kW·m –2 at 35 kW·m –2 of incident radiant heat flux. Furthermore, it demonstrates a reduced water absorption capacity, dropping from 5.12 g·g –1 to 0.75 g·g –1 . Altogether, this study opens the new pathways towards sustainable carbon-zero building materials in the context of circular bioeconomy.
An experimental program was conducted to evaluate the catalytic ignition of gaseous hydrogen and oxygen. Shell 405 granular catalyst and a unique monolithic sponge catalyst were tested. Mixture ratio, mass flow rate, propellant inlet temperature, and back pressure were varied parametrically in testing to determine the operational limits of a catalytic igniter. The test results showed that the gaseous hydrogen/oxygen propellant combination can be ignited catalytically using Shell 405 catalyst over a wide range of mixture ratios, mass flow rates, and propellant injection temperatures. These operating conditions must be optimized to ensure reliable ignition for an extended period of time. The results of the experimental program and the established operational limits for a catalytic igniter using both the granular and monolithic catalysts are presented. The capabilities of a facility constructed to conduct the igniter testing and the advantages of a catalytic igniter over other ignition systems for gaseous hydrogen and oxygen are also discussed.