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Results for “Carbon Conversion”

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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

An alkali metal, such as lithium, is the anodic reactant; carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant; and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is, therefore, especially useful in extraterrestrial environments.

Hagedorn, Norman H.↗
NASA NTRS1984

Molten Slag Would Boost Coal Conversion

Reactor increases residence time of uncovered char. Near-100percent carbon conversion achievable in reactor incorporating moltenslag bath. Slag maintains unconverted carbon impinging on surface at high temperatures for longer period of time, enhancing conversion.

Ferrall, J. F.↗
NASA NTRSDate not supplied

Plasma Chemical Conversion and Resource Generation Beyond Low-Earth Orbit

As humanity gears up for its return to the moon after more than half a century, collaborative efforts between NASA, Artemis Accords Partners, and private industry are underway to establish the necessary infrastructure and technologies for lunar habitation and eventual Mars exploration. However, the traditional ISS resupply and waste management model is impractical and economically infeasible for prolonged missions to the Moon and Mars. Advanced chemical conversion technologies are needed to generate vital consumable products from local planetary resources (ISRU) and recycled gasses and waste within semi-closed loop life-support systems. Low-temperature plasma reactors are emerging power-to-gas technologies with the potential to facilitate various chemical synthesis processes with hardware commonality and redundancy. In plasma-based systems, electrical power is used to ionize a feedstock gas, creating a highly reactive environment that leverages electron excitation chemistry to break stable molecular bonds and form value added products. Unlike thermal chemical processes, plasma reactors operate at non-equilibrium conditions, allowing for lower-temperature operation and instantaneous start-up, making them adaptable to intermittent power availability. Moreover, their scalability permits deployment in both portable astronaut systems and large-scale industrial setups for colonies. One promising application of plasmas is for CO 2 conversion. Carbon dioxide comprises 96% of the Martian atmosphere and is a byproduct of human respiration, which typically must be scrubbed and vented from space habitats. A plasma source integrated with membrane separation technology could generate a stream of oxygen for life support and rocket propellant. CO 2 splitting may also be beneficial as a precursor to manufacture carbon-based products and fuels in situ, like methane, methanol, and polyethylene. Plasma-assisted CO 2 conversion is a simpler case to study without the concern of selectivity and is the first step toward complex chemical synthesis. This work presents preliminary experimental case study from a plasma reactor for CO 2 conversion and casts a vision for the potential of plasma technologies in a sub-architecture for resource production to enable the next generation of human spaceflight activities.

Plasma↗
NASA NTRS2013

Trash-to-Gas: Using Waste Products to Minimize Logistical Mass During Long Duration Space Missions

Just as waste-to-energy processes utilizing municipal landftll and biomass wastes are finding increased terrestrial uses, the Trash-to-Gas (TtG) project seeks to convert waste generated during spaceflight into high value commodities. These include methane for propulsion and water for life support in addition to a variety of other gasses. TtG is part of the Logistic Reduction and Repurposing (LRR) project under the NASA Advanced Exploration Systems Program. The LRR project will enable a largely mission-independent approach to minimize logistics contributions to total mission architecture mass. LRR includes technologies that reduce the amount of consumables that need to be sent to space, repurpose items sent to space, or convert wastes to commodities. Currently, waste generated on the International Space Station is stored inside a logistic module which is de-orbited into Earth's atmosphere for destruction. The waste consists of food packaging, food, clothing and other items. This paper will discuss current results on incineration as a waste processing method. Incineration is part of a two step process to produce methane from waste: first the waste is converted to carbon oxides; second, the carbon oxides are fed to a Sabatier reactor where they are converted to methane. The quantities of carbon dioxide, carbon monoxide, methane and water were measured under the different thermal degradation conditions. The overall carbon conversion efficiency and water recovery are discussed.

Hintze, Paul. E.↗
NASA NTRS2013

Trash-to-Gas: Using Waste Products to Minimize Logistical Mass During Long Duration Space Missions

Just as waste-to-energy processes utilizing municipal landftll and biomass wastes are finding increased terrestrial uses, the Trash-to-Gas (TtG) project seeks to convert waste generated during spaceflight into high value commodities. These include methane for propulsion and water for life support in addition to a variety of other gasses. TtG is part of the Logistic Reduction and Repurposing (LRR) project under the NASA Advanced Exploration Systems Program. The LRR project will enable a largely mission-independent approach to minimize logistics contributions to total mission architecture mass. LRR includes technologies that reduce the amount of consumables that need to be sent to space, repurpose items sent to space, or convert wastes to commodities. Currently, waste generated on the International Space Station is stored inside a logistic module which is de-orbited into Earth's atmosphere for destruction. The waste consists of food packaging, food, clothing and other items. This paper will discuss current results on incineration as a waste processing method. Incineration is part of a two step process to produce methane from waste: first the waste is converted to carbon oxides; second, the carbon oxides are fed to a Sabatier reactor where they are converted to methane. The quantities of carbon dioxide, carbon monoxide, methane and water were measured under the different thermal degradation conditions. The overall carbon conversion efficiency and water recovery are discussed

Hintze, Paul E.↗
NASA NTRS2004

Impregnation of Catalytic Metals in Single-Walled Carbon Nanotubes for Toxic Gas Conversion in Life Support System

Carbon nanotubes (CNTs) possess extraordinary properties such as high surface area, ordered chemical structure that allows functionalization, larger pore volume, and very narrow pore size distribution that have attracted considerable research attention from around the world since their discovery in 1991. The development and characterization of an original and innovative approach for the control and elimination of gaseous toxins using single walled carbon nanotubes (SWNTs) promise superior performance over conventional approaches due to the ability to direct the selective uptake of gaseous species based on their controlled pore size, increased adsorptive capacity due to their increased surface area and the effectiveness of carbon nanotubes as catalyst supports for gaseous conversion. We present our recent investigation of using SWNTs as catalytic supporting materials to impregnate metals, such as rhodium (Rh), palladium (Pd) and other catalysts. A protocol has been developed to oxidize the SWNTs first and then impregnate the Rh in aqueous rhodium chloride solution, according to unique surface properties of SWNTs. The Rh has been successfully impregnated in SWNTs. The Rh-SWNTs have been characterized by various techniques, such as TGA, XPS, TEM, and FTIR. The project is funded by a NASA Research Announcement Grant to find applications of single walled nanocarbons in eliminating toxic gas Contaminant in life support system. This knowledge will be utilized in the development of a prototype SWNT KO, gas purification system that would represent a significant step in the development of high efficiency systems capable of selectively removing specific gaseous for use in regenerative life support system for human exploration missions.

Li, Jing↗
NASA NTRS2016

Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

Oxygen Recovery↗
NASA NTRS2009

High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell

A new cell designed to mimic the photosynthetic processes of plants to convert carbon dioxide into carbonaceous products and oxygen at high efficiency, has an improved configuration using a polymer membrane electrolyte and an alkaline medium. This increases efficiency of the artificial photosynthetic process, achieves high conversion rates, permits the use of inexpensive catalysts, and widens the range of products generated by this type of process. The alkaline membrane electrolyte allows for the continuous generation of sodium formate without the need for any additional separation system. The electrolyte type, pH, electrocatalyst type, and cell voltage were found to have a strong effect on the efficiency of conversion of carbon dioxide to formate. Indium electrodes were found to have higher conversion efficiency compared to lead. Bicarbonate electrolyte offers higher conversion efficiency and higher rates than water solutions saturated with carbon dioxide. pH values between 8 and 9 lead to the maximum values of efficiency. The operating cell voltage of 2.5 V, or higher, ensures conversion of the carbon dioxide to formate, although the hydrogen evolution reaction begins to compete strongly with the formate production reaction at higher cell voltages. Formate is produced at indium and lead electrodes at a conversion efficiency of 48 mg of CO2/kilojoule of energy input. This efficiency is about eight times that of natural photosynthesis in green plants. The electrochemical method of artificial photosynthesis is a promising approach for the conversion, separation and sequestration of carbon dioxide for confined environments as in space habitats, and also for carbon dioxide management in the terrestrial context. The heart of the reactor is a membrane cell fabricated from an alkaline polymer electrolyte membrane and catalyst- coated electrodes. This cell is assembled and held in compression in gold-plated hardware. The cathode side of the cell is supplied with carbon dioxide-saturated water or bicarbonate solution. The anode side of the cell is supplied with sodium hydroxide solution. The solutions are circulated past the electrodes in the electrochemical cell using pumps. A regulated power supply provides the electrical energy required for the reactions. Photovoltaic cells can be used to better mimic the photosynthetic reaction. The current flowing through the electrochemical cell, and the cell voltage, are monitored during experimentation. The products of the electrochemical reduction of carbon dioxide are allowed to accumulate in the cathode reservoir. Samples of the cathode solution are withdrawn for product analysis. Oxygen is generated on the anode side and is allowed to vent out of the reservoir.

Narayan, Sri↗
NASA NTRS1980

OCS, stratospheric aerosols and climate

The carbonyl sulfide budget in the atmosphere is examined, and the effects of stratospheric sulfate aerosol particles, formed in part from atmospheric carbonyl sulfate, on global climate are considered. From tropospheric measurements of carbon disulfide and the rate constant for the conversion of carbon disulfide to carbonyl sulfide, it is estimated that five Tg of carbonyl sulfide/year could be generated from carbon disulfide in the atmosphere. Direct sources of OCS include the refining and combustion of fossil fuels (1 Tg/year), natural and agricultural fires (0.2 to 0.3 Tg/year), and soils (0.5 Tg/year), yielding a total influx of from 1 to 10 Tg/year, up to 50% of which may be anthropogenic. Considerations of carbonyl sulfide sinks and concentrations indicate an atmospheric lifetime of one year, with OCS the major atmospheric sulfur compound. It is estimated that a ten-fold increase in atmospheric carbonyl sulfide would cause an optical depth perturbation comparable to that of a modest volcanic eruption, leading to an average global surface temperature decrease of 0.1 K, in addition to a possible greenhouse effect.

Turco, R. P.↗
NASA NTRS1991

Reaction engineering for materials processing in space: Reduction of ilmenite by hydrogen and carbon monoxide

Oxygen is a consumable material which needs to be produced continuously in most space missions. Its use for propulsion as well as life support makes oxygen one of the largest volume chemicals to be produced in space. Production of oxygen from lunar materials is of particular interest and is very attractive possibility. The kinetics and mechanism of reduction of ilmenite by carbon monoxide and hydrogen at 800 to 1100 C were investigated. The temporal profiles of conversion for carbon monoxide have a sigmoidal shape and indicate the presence of three different stages (induction, acceleration, and deceleration) during the reduction reaction. The apparent activation energy decreases from 18 kcal/mole at 10 percent conversion to 10 kcal/mole at 50 percent conversion. The reaction is first order with respect to carbon monoxide under the experimental conditions studied. Both SEM and EDX analysis show that the diffusion of Fe product away from the reaction front and through the TiO2 phase, followed by the nucleation and growth of a separate Fe phase are important steps affecting the process kinetics. The results from hydrogen reduction show that the mechanism of ilmenite reduction by hydrogen is similar to that by carbon monoxide. However, the titanium dioxide can be further reduced by hydrogen at 800 to 1000 C. The detailed comparison and theoretical modeling of both reduction processes is presented.

Zhao, Y.↗
NASA NTRS1992

On-site manufacture of propellant oxygen from lunar resources

The Aerojet Carbothermal Process for the manufacture of oxygen from lunar resources has three essential steps: the reduction of silicate with methane to form carbon monoxide and hydrogen; the reduction of carbon monoxide with hydrogen to form methane and water; and the electrolysis of water to form oxygen and hydrogen. This cyclic process does not depend upon the presence of water or water precursors in the lunar materials; it will produce oxygen from silicates regardless of their precise composition and fine structure. Research on the first step of the process was initiated by determining some of the operating conditions required to reduce igneous rock with carbon and silicon carbide. The initial phase of research on the second step is completed; quantitative conversion of carbon monoxide and hydrogen to methane and water was achieved with a nickel-on-kieselguhr catalyst. The equipment used in and the results obtained from these process studies are reported in detail.

Rosenberg, Sanders D.↗
NASA NTRS1981

Photoproduction of halogens using platinized TiO2

Unlike electrolysis of halide salt solutions, technique using powdered titanium dioxide catalyst requires no external power other than ultraviolet radiation source. Semiconductor powders photocatalyze and photosynthesize many useful reactions; applications are production of halogen molecules, oxidation of hazardous materials in wastewater, and conversion of carbon monoxide to carbon dioxide.

Reichman, B.↗