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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 379 records · Page 21

Effect of changes of physical properties on CO2 capture solvents on its absorption rate

Concern over greenhouse gas emissions, such as CO2 from fossil fuel combustion, is leading to new regulations on fossil-fuel fired power generation facilities. Using amine-based solutions for CO2 capture in power plants is the most common method utilized industrially and studied in the laboratory environment. However, a limited number of amines are available for carbon capture research after balancing the capital cost and energy penalty. In the carbon capture process, physical properties such as viscosity, surface tension, wettability, etc. are found to play important roles in solvent performance. In this context, we are exploring an approach to enhance the CO2 capture of amine solvents by tuning the physical properties of the amine solvents by the addition of additives. These additives in the amine solution utilize controlled bubble generation to increase liquid-gas contact surface area. This method can increase mass transfer in the absorber column, specifically at the bottom where the mass transfer is limited. These additives can enhance the CO2 capture efficiency by changing the physical property of the solvent which in turn can lower the capital cost associated with the system. This work can be applied to all common aqueous amine solvent and would be of great interest to those in the CCS community.

20 FOSSIL-FUELED POWER PLANTS↗

Nuclear-pumped CO2 laser

The He-3 (n,p)T reaction was examined as an energy source for a CO2 laser. For this purpose He-3 was added to a functioning CO2 electrically excited laser. Initially the laser was run electrically with 12 torr total pressure. The gas mixture was 1:1:8, CO2:N2:He. At zero reactor power, the laser was tested in place next to the core of the Georgia Tech. Research Reactor. After verification of laser action He-3 was added to the system. The He-3 partial pressures of 10 torr, 50 torr, and 300 torr were added in three separate reactor runs. Reactor power ranged from zero to 5 million watts, which corresponds to a peak flux of 10 to the 14th power/sq cm. At reactor powers greater than 10 kW, gain of up to 30 percent was shown. However, indications are this may be due to gamma excitation rather than caused by the He-3 (n,p)T reaction. These results do agree with the data of past CO2 nuclear pumped laser experiments.

Rowe, M.↗

Human Support Technology Research to Enable Exploration

Contents include the following: Advanced life support. System integration, modeling, and analysis. Progressive capabilities. Water processing. Air revitalization systems. Why advanced CO2 removal technology? Solid waste resource recovery systems: lyophilization. ISRU technologies for Mars life support. Atmospheric resources of Mars. N2 consumable/make-up for Mars life. Integrated test beds. Monitoring and controlling the environment. Ground-based commercial technology. Optimizing size vs capability. Water recovery systems. Flight verification topics.

Joshi, Jitendra↗

Earth benefits of interdisciplinary CELSS-related research by the NSCORT in Bioregenerative Life Support

Earth benefits of research from the NSCORT in Bioregenerative Life Support will include the following: development of active control mechanisms for light, CO2, and temperature to maximize photosynthesis of crop plants during important phases of crop development; automation of crop culture systems; creation of novel culture systems for optimum productivity; creation of value-added crops with superior nutritional, yield, and waste-process characteristics; environmental control of food and toxicant composition of crops; new process technologies and novel food products for safe, nutritious, palatable vegetarian diets; creation of menus for healthful vegetarian diets with psychological acceptability; enzymatic procedures to degrade recalcitrant crop residues occurring in municipal waste; control-system strategies to ensure sustainabilty of a CELSS that will enable management of diverse complex systems on Earth.

NASA Discipline Number 93-10↗

Separation of spallation and terrestrial C-14 in chondrites

Weathering products and contamination severely hamper our ability to accurately measure the C-14 spallation component in meteorites, but can give insights into a sample's terrestrial history. A procedure was developed to measure the C-14 in these components using CO and CO2 separations from temperature extractions from 200-500 mg of material. The Bruderheim (L6) chondrite was chosen as a standard following the practice of previous researchers, crosschecked against Peace River (L6), Abee (EH4), and Juvinas (EUC). Low temperature fractions (less than 900 C) give C-14 signatures consistent with a modern terrestrial C-14 source; melt fractions show elevated levels attesting to a spallogenic origin. Higher yields of CO in the melt fraction are less affected by the low levels of experimental contamination than the CO2. This fraction gave a mean CO:CO2 ratio in Bruderheim of 81.6 +/- 7.7; the ratio of the spallation component is 79.8 +/- 8.1. These values suggest equilibrium release of gases on the olivine-silica-pyroxene-iron buffer. This is corroborated by approximately equal release of the two components at 900 C. The chondrites gave an average saturation level of 54.3 +/- 2.9 dpm/kg; the achondrite gave 49.6 +/- 2.0 dpm/kg. No clear correlation with oxygen content is apparent, though shielding effects have yet to be evaluated. A further evaluation of this subject matter is given.

Cresswell, R. G.↗

Critical Analysis of Replacements for R-410A in Heat Pump Applications

Using low-GWP refrigerants can reduce the Green House Gas (GHG) emission of HVAC systems. Research has shown that using heat exchangers with small diameter tubes is a promising solution to meet the performance goals of heat pump using low-GWP refrigerants due to reduced refrigerant charge, reduced flammable impact and environmental impact. However, application of small diameter tube requires in-depth component design optimization to make the new system adapt to low-GWP refrigerants.In this paper, multi-objective optimizations using Particle Swarm Optimization (PSO) algorithm on a R-410A residential 5-ton air source heat pump is performed for improved system performance and reduced material cost. Five R-410A alternatives, i.e., R-32, R-454A, R-454B, R-454C and R-455A are investigated. R-455A and R-454C have GWP lower than 150. As a result of optimization, 12.4%-19.1% Energy Efficiency Ratio (EER) improvement and up to 71% HXs material cost saving is achieved. Life Cycle Climate Performance (LCCP) analysis shows that optimized systems reduce total CO2 emission by 13%-33% depending on the choice of refrigerant and climate zone.The optimal heat exchangers resulting from this research can fit into the original R-410A fan-coil units. The proposed heat pump design method establishes a production and installation path to produce cost-effective low-GWP heat pumps easily accepted by end users.

Li, Zhenning↗

Selection of solvents for integrated CO 2 absorption and electrochemical reduction systems

Abstract Solvent‐based electrochemical CO 2 reduction (CO 2 R) enables the production of chemicals or fuels using CO 2 from a preceding absorption process. Employing previously tested CO 2 capture solvents does not ensure their suitability for either CO 2 R or integrated CO 2 absorption‐reduction. We propose solvent selection criteria that include the CO 2 solubility, kinetic constant, ionic conductivity, concentration of the bicarbonate, carbamate, and solvent cation in the CO 2 ‐loaded solution, and sustainability indicators. They are implemented for solvent selection (a) from novel, aqueous mixtures of N ‐methylcyclohexylamine (MCA) with piperazine (PZ), 2‐amino‐2‐methyl‐1‐propanol (AMP), potassium hydroxide (KOH), and potassium chloride (KCl) and (b) from aqueous monoethanolamine (MEA), AMP, KOH, MCA, and PZ solutions. Versions of a modified Kent‐Eisenberg model for strong bases, carbamate, and non‐carbamate‐forming amine solutions are developed and parameterized through experimental equilibrium measurements. CO 2 R experimental results are presented for solutions of KOH and MCA + KOH, as these indicate desired trade‐offs for CO 2 absorption and reduction.

Amines↗

Atmospheric laser Doppler velocimetry - An overview

Research, development, and application of atmospheric laser Doppler velocimetry are overviewed. Consideration is given to operation principles of CO2 heterodyne systems. Global wind, pollution, V/STOL flow, and true airspeed measurements are outlined. Wind energy, dust devils, water spouts, tornadoes, and aircraft wake vortices are covered.

Bilbro, J. W.↗

Control of Oscillatory Thermocapillary Convection in Microgravity

This project focused on the generation and suppression of oscillatory thermocapillary convection in a thin liquid layer. The bulk of the research was experimental in nature, some theoretical work was also done. ne first phase of this research generated, for the first time, the hydrothermal-wave instability predicted by Smith and Davis in 1983. In addition, the behavior of the fluid layer under a number of conditions was investigated and catalogued. A transition map for the instability of buoyancy-thermocapillary convection was prepared which presented results in terms of apparatus-dependent and apparatus-independent parameters, for ease of comparison with theoretical results. The second phase of this research demonstrated the suppression of these hydrothermal waves through an active, feed-forward control strategy employing a CO2 laser to selectively heat lines of negative disturbance temperature on the free surface of the liquid layer. An initial attempt at this control was only partially successful, employing a thermocouple inserted slightly below the free surface of the liquid to generate the control scheme. Subsequent efforts, however, were completely successful in suppressing oscillations in a portion of the layer by utilizing data from an infrared image of the free surface to compute hydrothermal-wave phase speeds and, using these, to tailor the control scheme to each passing wave.

Skarda, Ray↗

Development Status of Amine-based, Combined Humidity, CO2, and Trace Contaminant Control System for CEV

Under a NASA-sponsored technology development project, a multi-disciplinary team consisting of industry, academia, and government organizations lead by Hamilton Sundstrand is developing an amine-based humidity and CO2 removal process and prototype equipment for Vision for Space Exploration (VSE) applications. Originally this project sought to research enhanced amine formulations and incorporate a trace contaminant control capability into the sorbent. In October 2005, NASA re-directed the project team to accelerate the delivery of hardware by approximately one year and emphasize deployment on board the Crew Exploration Vehicle (CEV) as the near-term developmental goal. Preliminary performance requirements were defined based on nominal and off-nominal conditions and the design effort was initiated using the baseline amine sorbent, SA9T. As part of the original project effort, basic sorbent development was continued with the University of Connecticut and dynamic equilibrium trace contaminant adsorption characteristics were evaluated by NASA. This paper summarizes the University sorbent research effort, the basic trace contaminant loading characteristics of the SA9T sorbent, design support testing, and the status of the full-scale system hardware design and manufacturing effort.

Smith, Fred↗

Pseudorandom Noise Code-Based Technique for Cloud and Aerosol Discrimination Applications

NASA Langley Research Center is working on a continuous wave (CW) laser based remote sensing scheme for the detection of CO2 and O2 from space based platforms suitable for ACTIVE SENSING OF CO2 EMISSIONS OVER NIGHTS, DAYS, AND SEASONS (ASCENDS) mission. ASCENDS is a future space-based mission to determine the global distribution of sources and sinks of atmospheric carbon dioxide (CO2). A unique, multi-frequency, intensity modulated CW (IMCW) laser absorption spectrometer (LAS) operating at 1.57 micron for CO2 sensing has been developed. Effective aerosol and cloud discrimination techniques are being investigated in order to determine concentration values with accuracies less than 0.3%. In this paper, we discuss the demonstration of a PN code based technique for cloud and aerosol discrimination applications. The possibility of using maximum length (ML)-sequences for range and absorption measurements is investigated. A simple model for accomplishing this objective is formulated, Proof-of-concept experiments carried out using SONAR based LIDAR simulator that was built using simple audio hardware provided promising results for extension into optical wavelengths. Keywords: ASCENDS, CO2 sensing, O2 sensing, PN codes, CW lidar

Campbell, Joel F.↗

Experimental Investigation of Vapor Formation in Liquid CO2 Flow Through a Converging-Diverging Nozzle

Carbon dioxide is an attractive working fluid for many cycles, including for pumped thermal energy storage (PTES). A challenge with some proposed sCO2 PTES cycles is the operation of sCO2 machinery outside the typical bounds of experience, with local phase change from the liquid state being particularly unknown. Presently, there is insufficient data in the literature regarding multiphase CO2 to adequately design a multiphase-tolerant turbine, so generation of foundational data is required. This experimental study investigates the flow characteristics of sub-sonic liquid CO2 undergoing expansion and phase change in a converging-diverging nozzle. The nozzle is instrumented to measure static pressure, unsteady pressure, temperature, and density. The static pressure transducers are located at 27 axial locations to accurately characterize the pressure profile in the nozzle. High-accuracy RTDs are located at the entrance and exit of the nozzle, and three dynamic pressure transducers are strategically located to capture any unsteady phenomena. During testing, values of mass flow and nozzle inlet pressure are swept to vary the pressure drop and fluid properties. The measured total pressure drop in the nozzle is compared to a homogenous model and the Lockhart-Martinelli correlation method, with the latter predicting loss quite closely. The resulting data set is valuable for validating multiphase numerical models in a simple geometry before implementation of these models in turbomachinery design.

25 ENERGY STORAGE↗

Analysis of Oxygen Spectral Lines in the 1.27 Micron Band for the ASCENDS Mission

The ASCENDS mission requires simultaneous laser remote sensing of CO2 and O2 in order to convert CO2 column number densities to average column CO2 mixing ratios (XCO2). As such, the CO2 column number density and the O2 column number density will be utilized to derive the average XCO2 column. NASA Langley Research Center, working with its partners, is developing O2 lidar technology in the 1.26-1.27- m band for surface pressure measurements. The O2 model optical depth calculation is very sensitive to knowledge of the transmitted wavelengths and to the choice of Voigt input parameters. Modeling using the HITRAN database is being carried out to establish the evolution of candidate O2 absorption lines as a function of atmospheric parameters such as altitude, temperature, and pressure. Preliminary results indicate limitations of the Voigt profile and the need to utilize more advanced models which take into account line mixing, line narrowing, and speed dependence. In this paper, we evaluate alternative lineshape models to establish the optimum lineshapes which better account for the variability of individual O2 absorption lines at various atmospheric conditions. The combination of our modeling efforts with accurate laboratory measurements is anticipated to aid in achieving the desired CO2 mixing ratio measurement accuracy requirement of for the ASCENDS mission.

Pliutau, Denis↗

High-Peak-Power Long-Wave Infrared Lasers with CO2 Amplifiers

Long-wave infrared (LWIR) picosecond pulses with multi-terawatt peak power have recently become available for advanced high-energy physics and material research. Multi-joule pulse energy is achieved in an LWIR laser system via amplification of a microjoule seed pulse with high-pressure, mixed-isotope CO 2 amplifiers. A chirped-pulse amplification (CPA) scheme is employed in such a laser to reduce the nonlinear interaction between the optical field and the transmissive elements of the system. Presently, a research and development effort is underway towards an even higher LWIR peak power that is required, for instance, for promising particle acceleration schemes. The required boost of the peak power can be achieved by reducing the pulse duration to fractions of a picosecond. For this purpose, the possibility of reducing the gain narrowing in the laser amplifiers and post-compression techniques are being studied. Another direction in research is aimed at the increased throughput (i.e., repetition rate), efficiency, and reliability of LWIR laser systems. The transition from a traditional electric-discharge pumping to an optical pumping scheme for CO 2 amplifiers is expected to improve the robustness of high-peak-power LWIR lasers, making them suitable for broad implementation in scientific laboratory, industrial, and clinical environments.

43 PARTICLE ACCELERATORS↗

The Effect of Rapid Development on Soil CO2 Efflux in a Cellulosic Biofuel Stand

As awareness of climate change increases, the need for carbon neutral fuel sources is growing. Lignocellulosic biofuel derived from pine trees has been suggested as one potential energy source; however, it requires more research before its efficacy for climate change mitigation can be determined. Due to the large share of forest carbon held in soils and the extensive area of pine plantations in the southeast U.S., a better understanding of plantation soil carbon dynamics is critical for biofuel carbon accounting. This study evaluated the effects of canopy development and productivity on soil CO2 efflux, a proxy for soil respiration (Rs), in an intensively managed loblolly pine (Pinus taeda) stand over a period from May 2015 to December 2019. We found that leaf area index (LAI) and gross ecosystem production (GEP), as well as meteorological variables, had significant effects on Rs, but that both overall Rs and soil carbon pools did not increase over the course of the study. We thus hypothesize that GEP and LAI had intra-annual effects on Rs, and that the lack of change in Rs is the result of an increase in autotrophic respiration (Ra) that offset a decrease in decomposition of the previous stand’s organic matter.

09 BIOMASS FUELS↗

AEOLIAN INTERDUNE FACIES OF THE NAVAJO SANDSTONE, UTAH

During the Early Jurassic an extensive desert environment covered a large area of the Western Interior of the USA. The Navajo Sandstone erg is thought to be one of the largest dunefields preserved in the rock record, estimated to have covered well over 500,000 km2, though the preserved extent is less due to erosion. The Navajo Sandstone outcrops extensively in eastern and southern Utah, forming spectacular domes and arches, including those in Arches National Park. Navajo Sandstone aeolian dunes consist of stacked, tabular sandstone bodies, displaying steeply dipping crossbedding, and are on average 15 m thick, with high porosity and permeability. In addition to these extensive paleodunes, interdune deposits are also documented, consisting of lensoid sandstone or pale grey limestone, of approximately 1-7 m thick. This research forms part of a broader investigation into the Navajo Sandstone in Utah, focusing on its potential as a CO2 reservoir. The internal stratigraphy of the Navajo Sandstone can be complex, with multiple types of aeolian surfaces present including discontinuous inter-dune contacts, and inclined bedding planes associated with large climbing dunes. Interdune deposits may be associated with more laterally extensive stratigraphic surfaces, highlighting their importance in the internal stratigraphic framework of the Navajo Sandstone erg. Here we interpret facies and depositional processes of aeolian interdune deposits of the Navajo Sandstone throughout Utah, using well log, outcrop, and thin sections. Interdune deposits range in type from short lived, small ponds of predominantly reworked aeolian sediment, to comparatively long-lived oases consisting of lakes with extensive ecosystems. This project aims to increase our understanding of an important potential CO2 reservoir, and enhance understanding of stratigraphic complexity within one of the world's most significant aeolian systems.

Mahon, Elizabeth (ORCID:0000000252692454)↗

Evaluation of candidate Stirling engine heater tube alloys after 3500 hours exposure to high pressure doped hydrogen or helium

The heater head tubes of current prototype automotive Stirling engines are fabricated from alloy N-155, an alloy which contains 20 percent cobalt. Because the United States imports over 90 percent of the cobalt used in this country and resource supplies could not meet the demand imposed by automotive applications of cobalt in the heater head (tubes plus cylinders and regenerator housings), it is imperative that substitute alloys free of cobalt be identified. The research described herein focused on the heater head tubes. Sixteen alloys (15 potential substitutes plus the 20 percent Co N-155 alloy) were evaluated in the form of thin wall tubing in the NASA Lewis Research Center Stirling simulator materials diesel fuel fired test rigs. Tubes filled with either hydrogen doped with 1 percent CO2 or with helium at a gas pressure of 15 MPa and a temperature of 820 C were cyclic endurance tested for times up to 3500 hr. Results showed that two iron-nickel base superalloys, CG-27 and Pyromet 901 survived the 3500 hr endurance test. The remaining alloys failed by creep-rupture at times less than 3000 hr, however, several other alloys had superior lives to N-155. Results further showed that doping the hydrogen working fluid with 1 vol % CO2 is an effective means of reducing hydrogen permeability through all the alloy tubes investigated.

Misencik, J. A.↗