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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Coal and Coal Wastes to High-Quality Graphite for Lithium-Ion Battery Applications

Conference presentation for 2023 International Freiberg Conference on Circular Carbon Technologies, Rotterdam, Netherlands, September 24–29, 2023. To assist in meeting the global graphite supply limitations, this study aims to investigate efficient ways to synthesize high-quality graphite from abundant coal and coal waste resources that exist in many areas around the world. A recently developed upgraded coal-to-products (UCP) process has shown great promise in the ability to reduce coal-borne impurities and produce a graphitizable product that yields good quality graphite for LIB applications. Preliminary results show that the quality of coal-derived graphite obtained by the UCP process is similar to that of commercial flake graphite. Available results are presented and discussed as well as maturation plans and flexibility of the UCP technology.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2021

Reburning of Animal Waste Based Biomass with Coal for NO x Reduction, Part I: Feedlot Biomass (FB) and Coal:FB Blends

Cattle biomass (CB or manure from cattle) is proposed as reburn fuel under slightly fuel-rich conditions. The CB includes wastes from cattle feedlots (cattle grown in feedlots to slaughter weights of 450–640 kg) termed as Feedlot Biomass (FB) and cattle wastes from dairy farms termed as Dairy Biomass (DB). NOx emissions from coal-fired power plants can be reduced by using pure CB and Coal:CB mixtures as reburn fuels (10~30% by heat) injected after the primary combustion region. Experiments with Coal:CB mixtures as reburn fuels were performed using the 30 kW burner facility. Part I deals with results from experiments using pure FB and Coal:FB blends as reburn fuels while Part II presents results on extent of NOx reduction using pure DB and Coal:DB blends as reburn fuels (RF). In the current work, results on NOx emission are presented with FB and Coal:FB blends as RF. The parametric studies include: equivalence ratio in reburn zone (ERRBZ), vitiated air, angle of reburn nozzles, presence and absence of heat exchangers (HEXs), and baseline NOx concentration. The optimum operating conditions for FB reburning were found to be conditions with vitiation at ERRBZ = 1.1 with 45° upward counter-current injection in the presence of HEXs. NOx emissions were reduced by as much as 96%.

09 BIOMASS FUELS↗
DOE OSTI2018

Coal Upgrading Technologies and the Extraction of Useful Materials from Coal Mine Products: History and Opportunities

This report will develop topics that may, resultant from successful research and development (R&D), improve the competitive position of United States coal in domestic and international markets. These topics will be exclusively focused on improvements in coal properties that can be achieved through processing of the material. As such, the discussion here will be primarily concerned with upgrading coal quality and optimizing coal properties for end use applications, as opposed to the end use technologies themselves. The objective of this report is the highlighting of the potential for R&D to produce more competitive coal products for existing markets, as well as opportunities for the production of feedstocks for other markets, including those that are emergent.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2022

Fundamental Studies on the Recovery of Rare Earth Elements from Coal and Coal Byproducts (Final Product Report)

The objective of this project was to collect fundamental information that can be used to develop disruptive physical and chemical separation methods that may be used to extract the rare earth elements (REEs) from coal-based feedstocks in a highly efficient, cost-effective, and environmentally benign manner. To meet the stated objective, a set of interrelated fundamental studies have been conducted. The project has been subdivided into three broad areas of tasks as follows, (1) measurement of surface forces in the thin liquid films (TLFs) of water confined between two macroscopic surfaces to establish the optimal conditions for efficiently collecting the ultrafine particles of rare earth minerals (REMs) present in the coal-based feedstocks using the flotation and/or the hydrophobic-hydrophilic separation process(es), (2) identification of the fundamental mechanisms by which REE ions adsorb and desorb on clay minerals present in coal byproducts, and the characterization of the ion-adsorption clays (IACs) present in U.S. coals, and (3) developing methods of extracting the REEs from the REMs and IACs present in US coal byproducts in a cost-effective and sustainable manner.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2022

CO 2 utilization potential of a novel calcium ferrite based looping process fueled with coal: Experimental evaluation of various coal feedstocks and thermodynamic integrated process analysis

Here, conversion of CO 2 to CO was performed at 800-850C via reduction of calcium ferrite (CaFe 2 O 4 ) with coal followed by oxidation of reduced CaFe 2 O 4 with CO 2 to produce CO and partially oxidized Ca ferrite. The process was evaluated with several types of coals which included lignite, sub-bituminous, bituminous, anthracite and pet-coke. Reduction of CaFe 2 O 4 with sub-bituminous coal and lignite coal was more favorable than that with higher rank coals. Stable reactivity performance was demonstrated for 35-cycle test conducted with lignite coal/CaFe 2 O 4 at 800°C and with high conversion of CO 2 to CO. The rate of conversion of CO 2 to CO with reduced CaFe 2 O 4 was found to be 1st order with respect to CO 2 and had a low activation energy of 7.4 kJ/mol. Thermodynamic integrated process assessments suggest that two and three reactor process concepts can be realized and net CO 2 utilization achievable. The two reactor configuration shows the highest potential for CO 2 utilization while generating a value-added CO rich syngas stream.

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

Removal of iodine (I- and IO3-) from aqueous solutions using CoAl and NiAl layered double hydroxides

The treatment of radioactive iodine released from nuclear power plants and radiological waste disposal sites is of great concern due to its high mobility and toxicity. In particular, iodide (I-) and iodate (IO3-) are the major iodine species of concern under various pHs and groundwater conditions. Herein, CoAl and NiAl layered double hydroxides (LDHs) were synthesized by a hydrothermal method and investigated to identify the removal mechanisms and efficiencies of both I- and IO3-. Both CoAl and NiAl LDHs exhibited rapid iodine removal processes within 20 min, following the pseudo-second-order model via ion-exchange with parent NO3- anion in the LDHs. The CoAl LDH’s maximum sorption capacities for I- and IO3- were about 1.67 and 2.16 mmol g-1, respectively, whereas for the NiAl LDH, these were about 2.10 and 2.26 mmol g-1, and they followed the Langmuir isotherm model. Interestingly, both the CoAl and NiAl LDHs showed a preferential ion-exchange affinity for IO3- over I-, which was attributed to the structural similarity of the IO3- and NO3- as well as new formation of secondary Co(or Ni)(IO3)2·2H2O phases. In addition, a desorption study indicated that the selectivity order was SO42- = IO3- = OH- > HCO3- > Cl- > NO3- = I- and demonstrated the higher retention of the IO3- than I- anion. This study provides insights into promising iodine sorbents and the different removal mechanisms of I- and IO3- using CoAl and NiAl LDHs.

Kang, Jaehyuk↗
DOE OSTI2019

Computational simulation of a 100 kW dual circulating fluidized bed reactor processing coal by chemical looping with oxygen uncoupling

Chemical looping with oxygen uncoupling (CLOU) is a promising carbon capture technology that utilizes two interconnected fluidized-bed reactors to separate oxygen from air using a metal oxide, and then to use that oxygen to combust fuel in a nitrogen-free environment. CLOU is particularly well suited for solid fuels such as coal since released O 2 will readily combust with solid char. This study presents simulations of the University of Utah's dual fluidized bed chemical looping process development unit (PDU) operating as a CLOU system at 100 kW th , using CPFD Software's Barracuda-VR™ CFD modeling program. A full 3D model of the PDU was used including both reactors, as well as loop seals and cyclone separators. Hydrodynamic settings and the drag model are based on previous cold-flow validation experiments. Mechanisms describing CLOU reaction kinetics for cuprous oxide oxidation in the air reactor and cupric oxide reduction in the fuel reactor were adapted from previously completed experimental work. Coal char kinetics were based on the carbon-hydrogen-nitrogen-oxygen-sulfur, CHNOS, method. Submodels for devolatilization, gasification, and homogenous gas-phase reactions used relationships from the literature. Results predict volatile burnout almost immediately, though coal combustion continues into the upper portions of the fuel reactor and cyclone. Lastly, nitrogen gas leakage into the fuel reactor is shown to be mostly carryover from the air reactor

42 ENGINEERING↗
NASA NTRS1978

New method of feeding coal - Continuous extrusion of fully plastic coal

Continuous feeding of coal in a compressing screw extruder is described as a method of introducing coal into pressurized systems. The method utilizes the property of many bituminous coals of softening at temperatures from 350 to 400 C. Coal is then fed much in the manner of common thermoplastics, using screw extruders. Preliminary results show that coals can be extruded at rates of about 3.3 kg/MJ, similar to those for plastics.

Ryason, P. R.↗
DOE OSTI2019

Structure and Reactivity of Low-Rank Coal Chars Prepared from Fluidized Bed and Moving Bed Pyrolyzers and the Potential for Using Them in Pulverized Coal Injection (PCI)

Utilizing pyrolysis chars as the injection fuel in a blast furnace can reduce the dependence on high-quality pulverized coal injection (PCI) coal. In this study, the physical properties and reaction characteristics of chars prepared from two different industrial-scale pyrolyzers (fluidized bed and moving bed) are investigated. The results reveal remarkable component segregation in the char particles with different particle sizes. The properties of large-size char particles are found to better satisfy the PCI fuel requirement in a blast furnace. Compared with PCI coal, the char particles exhibit a rough surface, well-developed pore structure, and less-ordered chemical structure of carbon. Results from isothermal combustion, isothermal gasification, and drop tube furnace experiments show that both types of chars exhibit a better reactivity than PCI coal. The excellent reactivity of chars is closely related to its high Brunauer–Emmett–Teller surface area and relatively poor chemical ordering during conversion. Based on these characteristics, both fluidized bed char (FBC) and moving bed char (MBC) have a great potential to be used as PCI fuels. The application method of chars for PCI in a blast furnace is proposed finally.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2019

Enhancement of a Process Flowsheet for Recovering and Concentrating Critical Materials from Bituminous Coal Sources

Recovery of rare earth elements (REE) from coal-related resources has recently received significant interest due to supply concerns and their key roles in critical industries and defense-related technologies. In this study, an integrated flowsheet consisting of sorting, crushing/grinding, physical separation, acid leaching, solvent extraction, and selective precipitation was designed to achieve continuous production of rare earth products from various coal-related resources such as coarse refuse and acid mine drainage. A pilot plant was constructed that enabled continuous testing of the circuitry on a range of different coal-based feedstocks. Despite achieving significant success in producing high-grade rare earth oxide products, low REE recovery values and high operational costs necessitated a re-evaluation of the process flowsheet. This article describes the circuitry improvements that were based on both laboratory and pilot plant test results. Roasting as a pre-leach treatment was found to significantly improve the leaching rate and overall REE recovery values. After roasting West Kentucky No. 13 and Fire Clay coal refuse materials at 600 °C, REE recovery increased by 60 and 40 absolute percentage points, respectively. Rare earth concentration in the pregnant leachate solution (PLS) was increased to around 700 ppm prior to solvent extraction using a staged precipitation method. REEs in the precipitate were re-dissolved, purified, and extracted from the PLS using solvent extraction and selective precipitation to values of around 80%. As a result of the improvements, chemical consumption in the acid leaching and solvent extraction processes was significantly reduced. A techno-economical assessment of the improved flowsheet indicated significant commercialization potential.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2013

Isotopic evidence of enhanced carbonate dissolution at a coal mine drainage site in Allegheny County, Pennsylvania, USA

Stable isotopes were used to determine the sources and fate of dissolved inorganic C (DIC) in the circumneutral pH drainage from an abandoned bituminous coal mine in western Pennsylvania. The C isotope signatures of DIC (δ{sup 13}C{sub DIC}) were intermediate between local carbonate and organic C sources, but were higher than those of contemporaneous Pennsylvanian age groundwaters in the region. This suggests a significant contribution of C enriched in {sup 13}C due to enhanced carbonate dissolution associated with the release of H{sub 2}SO{sub 4} from pyrite oxidation. The Sr isotopic signature of the drainage was similar to other regional mine waters associated with the same coal seam and reflected contributions from limestone dissolution and cation exchange with clay minerals. The relatively high δ{sup 34}S{sub SO4} and δ{sup 18}O{sub SO4} isotopic signatures of the mine drainage and the presence of presumptive SO{sub 4}-reducing bacteria suggest that SO{sub 4} reduction activity also contributes C depleted in {sup 13}C isotope to the total DIC pool. With distance downstream from the mine portal, C isotope signatures in the drainage increased, accompanied by decreased total DIC concentrations and increased pH. These data are consistent with H{sub 2}SO{sub 4} dissolution of carbonate rocks, enhanced by cation exchange, and C release to the atmosphere via CO{sub 2} outgassing.

01 COAL, LIGNITE, AND PEAT↗