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At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on MgCd(CO3)2 by Materials Project

CdMg(CO3)2 is Calcite-derived structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Mg2+ is bonded to six equivalent O2- atoms to form MgO6 octahedra that share corners with six equivalent CdO6 octahedra. The corner-sharing octahedral tilt angles are 62°. All Mg–O bond lengths are 2.11 Å. Cd2+ is bonded to six equivalent O2- atoms to form CdO6 octahedra that share corners with six equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 62°. All Cd–O bond lengths are 2.36 Å. C4+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All C–O bond lengths are 1.30 Å. O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Cd2+, and one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgCd3(CO3)4 by Materials Project

MgCd3(CO3)4 is Calcite-derived structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Mg2+ is bonded to six equivalent O2- atoms to form MgO6 octahedra that share corners with six equivalent CdO6 octahedra. The corner-sharing octahedral tilt angles are 63°. All Mg–O bond lengths are 2.13 Å. There are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to six equivalent O2- atoms to form corner-sharing CdO6 octahedra. The corner-sharing octahedral tilt angles are 61°. All Cd–O bond lengths are 2.32 Å. In the second Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with three equivalent MgO6 octahedra and corners with three equivalent CdO6 octahedra. The corner-sharing octahedra tilt angles range from 61–63°. There are three shorter (2.33 Å) and three longer (2.37 Å) Cd–O bond lengths. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All C–O bond lengths are 1.30 Å. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All C–O bond lengths are 1.30 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Cd2+, and one C4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cd2+ and one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCO3 by Materials Project

SrCO3 is Calcite-like structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. Sr2+ is bonded to six equivalent O2- atoms to form distorted corner-sharing SrO6 pentagonal pyramids. All Sr–O bond lengths are 2.54 Å. C4+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All C–O bond lengths are 1.30 Å. O2- is bonded in a distorted trigonal planar geometry to two equivalent Sr2+ and one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoAl3(BO3)4 by Materials Project

HoAl3(BO3)4 is Calcite-derived structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ho3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are four shorter (2.33 Å) and two longer (2.34 Å) Ho–O bond lengths. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form edge-sharing AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.95 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form edge-sharing AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.95 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.37–1.39 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.38 Å) and two longer (1.39 Å) B–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ho3+, one Al3+, and one B3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one B3+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ho3+, one Al3+, and one B3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one B3+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ho3+, one Al3+, and one B3+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one B3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaNO3 by Materials Project

NaNO3 is Calcite-like structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. Na1+ is bonded to six equivalent O2- atoms to form distorted corner-sharing NaO6 pentagonal pyramids. All Na–O bond lengths are 2.45 Å. N5+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All N–O bond lengths are 1.27 Å. O2- is bonded in a trigonal planar geometry to two equivalent Na1+ and one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TbAl3(BO3)4 by Materials Project

TbAl3(BO3)4 is Calcite-derived structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. Tb3+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Tb–O bond lengths are 2.35 Å. Al3+ is bonded to six O2- atoms to form edge-sharing AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.95 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.38 Å) and one longer (1.39 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All B–O bond lengths are 1.39 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one B3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Tb3+, one Al3+, and one B3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one B3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YbYAl6(BO3)8 by Materials Project

YbYAl6(BO3)8 is Calcite-derived structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. Yb3+ is bonded to six equivalent O2- atoms to form distorted YbO6 pentagonal pyramids that share corners with six equivalent AlO6 octahedra. The corner-sharing octahedral tilt angles are 59°. All Yb–O bond lengths are 2.37 Å. Y3+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Y–O bond lengths are 2.35 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent YbO6 pentagonal pyramids and edges with two equivalent AlO6 octahedra. There is two shorter (1.86 Å) and four longer (1.95 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form edge-sharing AlO6 octahedra. There is two shorter (1.88 Å) and four longer (1.94 Å) Al–O bond length. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.36 Å) and two longer (1.39 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All B–O bond lengths are 1.38 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one B3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one B3+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Y3+, one Al3+, and one B3+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Yb3+, one Al3+, and one B3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnCO3 by Materials Project

MnCO3 is Calcite-like structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mn2+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Mn–O bond distances ranging from 2.19–2.26 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. All C–O bond lengths are 1.30 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mn2+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mn2+ and one C4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mn2+ and one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdFe6Bi(BO3)8 by Materials Project

NdFe6Bi(BO3)8 is Calcite-derived structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. Nd3+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Nd–O bond lengths are 2.41 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.00 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.07 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All B–O bond lengths are 1.39 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.38 Å) and one longer (1.39 Å) B–O bond length. Bi3+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Bi–O bond lengths are 2.42 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one B3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Fe3+ and one B3+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+, one Fe3+, and one B3+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Fe3+, one B3+, and one Bi3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaNO3 by Materials Project

NaNO3 is Calcite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted corner-sharing NaO6 octahedra. The corner-sharing octahedra tilt angles range from 62–67°. There are a spread of Na–O bond distances ranging from 2.44–2.64 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.43–2.79 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form corner-sharing NaO6 octahedra. The corner-sharing octahedra tilt angles range from 62–66°. There are a spread of Na–O bond distances ranging from 2.32–2.47 Å. In the fourth Na1+ site, Na1+ is bonded to six O2- atoms to form corner-sharing NaO6 octahedra. The corner-sharing octahedra tilt angles range from 64–67°. There are a spread of Na–O bond distances ranging from 2.39–2.52 Å. There are four inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.26 Å) and two longer (1.27 Å) N–O bond length. In the second N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. All N–O bond lengths are 1.27 Å. In the third N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. All N–O bond lengths are 1.27 Å. In the fourth N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. All N–O bond lengths are 1.27 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and one N5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+ and one N5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one N5+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the tenth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the eleventh O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom. In the twelfth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YFe3(BO3)4 by Materials Project

YFe3(BO3)4 is Calcite-derived structured and crystallizes in the trigonal P3_121 space group. The structure is three-dimensional. Y3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Y–O bond distances ranging from 2.34–2.41 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.00–2.06 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.00–2.09 Å. There are three inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.38 Å) and two longer (1.39 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.38 Å. In the third B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.37–1.39 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Y3+, one Fe3+, and one B3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Fe3+ and one B3+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Y3+, one Fe3+, and one B3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Fe3+ and one B3+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Y3+, one Fe3+, and one B3+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Fe3+ and one B3+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Fe3+ and one B3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca5TiSn4(BO3)10 by Materials Project

Ca5TiSn4(BO3)10 is Calcite-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one TiO6 octahedra and corners with five SnO6 octahedra. The corner-sharing octahedra tilt angles range from 57–59°. There are a spread of Ca–O bond distances ranging from 2.39–2.47 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six SnO6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are five shorter (2.38 Å) and one longer (2.39 Å) Ca–O bond lengths. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent SnO6 octahedra and corners with four equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are two shorter (2.37 Å) and four longer (2.46 Å) Ca–O bond lengths. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six CaO6 octahedra. The corner-sharing octahedra tilt angles range from 57–59°. There is four shorter (1.99 Å) and two longer (2.00 Å) Ti–O bond length. There are five inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.39 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.39 Å. In the third B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.39 Å. In the fourth B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.38 Å) and two longer (1.39 Å) B–O bond length. In the fifth B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.39 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six CaO6 octahedra. The corner-sharing octahedra tilt angles range from 57–58°. There are one shorter (2.08 Å) and five longer (2.09 Å) Sn–O bond lengths. In the second Sn4+ site, Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six CaO6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Sn–O bond lengths are 2.09 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ti4+, and one B3+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ti4+, and one B3+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one B3+, and one Sn4+ atom. In the fifteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ti4+, and one B3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Structural analyses of amorphous calcium carbonate before and after removing strontium ions from an aqueous solution

Amorphous calcium carbonate (ACC) is a precursor of crystalline calcium carbonate; hence, its structural information at the atomic level is very important for controlling the morphology of crystalline calcium carbonate. In this study, we attempted to elucidate the process of Sr extraction from aqueous solution by using ACC for the purpose of removal of radioactive Sr from the contaminated water leaked after the Fukushima Daiichi nuclear accident. Here, the pair distribution functions, g(r) obtained by X-ray and neutron diffraction (ND) measurements show that ACC has a structure partially similar to that of monohydrocalcite, suggesting that ACC is transferred to the crystalline calcium carbonate starting from its crystal nucleus. Rietveld analysis of the ND data showed that the ACC that removed Sr was crystallized to calcite. However, the Sr–O coordination analyzed using extended X-ray absorption fine structure (EXAFS) implies that the local environment of O around Sr is similar to that in crystalline calcium carbonate aragonite.

36 MATERIALS SCIENCE↗
DOE OSTI2024

High-temperature Raman spectroscopy of K 2 Ca(CO 3 ) 2 bütschliite and Na 2 Ca 2 (CO 3 ) 3 shortite

Raman spectra of Na 2 Ca 2 (CO 3 ) 3 shortite and K 2 Ca(CO 3 ) 2 bütschliite were measured to 715°C and 740°C respectively, under vacuum. The vibrational spectra demonstrate that shortite converts to nyerereite (Na 2 Ca(CO 3 ) 2 ) and calcite at 535°C. This assemblage is stable to ~700°C, where nyerereite begins to decompose. Bütschliite converts to the isochemical phase fairchildite at 570°C, which is stable to 665°C, where it decomposes to an assemblage of K 2 CO 3 and CaO. The variation of anharmonicity between different vibrational modes of each of the low temperature phases is assessed, and these yield insights into inter-carbonate group couplings. In conclusion, both fairchildite and nyerereite exhibit spectral features consistent with extensive disordering.

58 GEOSCIENCES↗
DOE OSTI2021

Evolution of Pore Structure and Permeability of Rocks Under Hydrothermal Conditions (Final Report)

The physical and transport properties of porous rocks can be altered by a variety of diagenetic, metamorphic, and tectonic processes, and the changes that result are of critical importance to such industrial applications as resource recovery, carbon dioxide sequestration, and waste isolation in geologic formations. The associated interrelationships between rocks, pore fluids and deformation are also key to understanding many natural processes, including dynamic metamorphism, fault mechanics, fault stability and pressure solution creep. In this project, we investigated the changes of permeability and pore geometry owing to inelastic deformation by solution-transfer, brittle fracturing and dislocation creep. In particular, we studied the coupling between pore fluids and deformation in fluid-filled quartz, calcite, mudstones and ultramafic rocks and examine the effects of coupled mechanical and chemical processes on the evolution of porosity and permeability under hydrothermal conditions. The investigations used a combination of techniques, that included triaxial laboratory experiments; uniaxial compressive loading with in situ observations of microstructure; permeability under hydrostatic compression; observations of microstructure using optical and electron microscopes, and micro-CT imaging; and numerical calculations. Laboratory experiments were designed to provide mechanical and transport data under conditions that isolate the particular mechanisms responsible for the changes. The data obtained were used to quantify changes in surface roughness, porosity, pore dimensions and their spatial fluctuations. The results of the experiments and data from image analyses were compared to the results of network, finite-difference and other numerical models to verify the validity of experimentally established relations between permeability and other rock properties. A bibliography for the period from 2015-2019 is appended below. New results obtained in the final year and the unfunded extension period are detailed below.

58 GEOSCIENCES↗
DOE OSTI2020

Potential Formation Damage: An Integrated Reservoir Characterization Study of the Naturally Fractured Carbonate Middle Duperow Formation at the Kevin Dome, Montana

In this study, we integrate geologic and engineering data of a naturally fractured carbonate reservoir at the Kevin Dome, Montana. Well test data are correlated with core description, geochemical and lithology study to determine the flow behavior and communication within the injection test interval and to the surrounding area. Based on a dual-continuum geologic model, numerical brine injection simulations are carried out to validate the interpretation results from our well test analytical models and forecast the probability of CO 2 injection success using current reservoir properties. As a result, our well test analytical models as well as lithology/core description suggest that fluid flow may be mainly restricted to the injection interval and the assumption of radial (horizontal) flow may be appropriate. The well test models also indicate that there is potentially formation damage with a positive skin factor although prior to brine injection well tests, well stimulation through acid treatment was performed. Our numerical simulation results appear to confirm this formation damage by showing additional pressure buildup in the injection data during later test periods. To explain this, acid may have dissolved dolomite then dolomite or calcite may have been formed again further into the matrix/fracture system. Another possible explanation is mechanical clogging of the fractures due to acid dissolving dolomite and dislodging fine grains. Our work also predicts that if no additional well stimulation is performed, the project will have a lower probability of successfully injecting 1 million tons of CO 2 into the Middle Duperow formation over 4 years.

42 ENGINEERING↗
DOE OSTI2021

CO2 Capture Strategies via Mineralization with Industrial Waste Brines

Large coal-fired power plants (>500 MW) account for 30% of global CO2 emissions, and long-term management of this CO2 to is urgently needed mitigate global temperature increases. Sequestration of CO2 within stable mineral carbonates (e.g., CaCO3) represents an attractive emission reduction strategy because it offers a leakage-free alternative to geological storage of CO2 in an environmentally friendly form. We have previously described a mineralization process in which divalent cations are sourced from various waste streams (e.g., produced water and brackish water) and alkalinity is induced via regenerable ion-exchange materials (Bustillos et. al. Frontiers in Energy Research. 2020, 8, 352). In our process, aqueous carbonate-bearing streams with pH > 8 are produced by contacting fresh water and carbon dioxide with various ion-exchange materials (e.g., Na form zeolites or ion exchange resins). These streams are mixed with produced water containing varying concentrations (~0.01 – 1.0 M) of Ca2+ leading to the precipitation of solid calcium carbonate (PCC). This process has the advantages of using regenerable solids in a simple and continuous process to increase the pH of water by ion exchange instead of relying on the consumption of costly and unsustainable sources of alkalinity (e.g., sodium hydroxide). While once-through column experiments showed the above benefits, the same were yet to established in a steady-state process with recycle streams. In this work, we set up a process simulation to quantify the energy requirements and CO2 emissions associated with the process and seek optimal produced water compositions and CO2 concentrations (5 – 20 vol%). The process simulation was set up in ASPEN Plus using eRNTL as the thermodynamic property method and sequential modular strategy. Ion exchange alkaline solution was simulated using sodium hydroxide and validated against the experimental data obtained from once-through kinetic experiments. Nanofiltration and reverse osmosis membrane steps were also implemented for the separation of divalent cations and production of fresh water and a regeneration stream following mineralization. Sensitivity analysis was carried out using a range of produced water compositions (0.01 – 1.0 M Ca2+, 0.001 – 0.15 M Mg2+, 0.5 – 3.5 M Na+ and 0.0004 – 0.002 M Fe2+) according to the United States Geological Survey (USGS) database. Calcium carbonate yields increased with increasing CO2 concentrations and were maximized using produced water compositions with larger Ca2+ concentrations. Maximum calcium carbonate yields produced at 5 vol%, 12 vol% and 20 vol% CO2 were 2.3 mmol/L, 5.5 mmol/L, and 9.3 mmol/L, respectively, with the formation of brucite (a magnesium hydroxide phase, Mg(OH)2) and goethite (an iron hydroxide phase, FeOOH) as the primary contaminant phases (99% calcite, 0.6% brucite, 0.4% goethite), which agree with phases detected by XRD experimentally. These results indicate high purity calcium carbonate can be precipitated using industrial waste streams. Consequentially, energy consumption and net CO2 emissions were minimized where precipitated calcium carbonate was maximized for all produced water compositions and CO2 concentrations. Minimum energy consumptions were 0.21 kWh/ton CO2 processed, with 98% of the energy input required coming from the membrane filtration steps. Produced water compositions with large Na+ concentrations (> 0.5 M) were effective at reducing energy consumptions due to faster regeneration time of ion exchange materials. Additionally, calculated net CO2 emissions were negative for the process and ranged from -0.02 kg/ton CO2 to -0.15 kg/ton CO2 processed, indicating a low emission process. We will also present techno-economic assessment showing the economic benefits of the current process as an alternative to the addition of stoichiometric bases to induce alkalinity for the precipitation of CaCO3.

Simonetti, Dante↗
DOE OSTI2021

Fiscal Year 2021 Filtration of Hanford Tank 241-AP-107 Supernatant Samples Obtained at Prototypic Tank Level and Filtered at 16 °C

Bench-scale filtration testing of 8.5 liters of supernatant from Hanford waste tank 241-AP-107, chilled to 16 °C, was conducted using a backpulse dead-end filter (BDEF) filtration system equipped with a feed vessel and a Mott inline filter Model 6610 (Media Grade 5) in the hot cells of the Radiochemical Processing Laboratory at Pacific Northwest National Laboratory. This was done to assess the impact of a lower sampling location within the tank as well the lowered filtration temperature on supernatant stability and fouling. The as-received samples were transferred to 1.5-liter poly bottles and held at 16 °C for approximately 1 week prior to filtration. The feed was filtered through the BDEF system at a targeted flux of 0.065 gpm/ft 2 to match the prototypic operation of the TSCR system. During the initial period of filtration, the differential pressure required to effect filtration at 0.065 gpm/ft 2 increased until it reached 2 psid [the Tank Side Cesium Removal (TSCR) action limit] at 26 hours. After this, the filter was backpulsed to dislodge accumulated solids and reduce this pressure differential. An additional eight backpulses were conducted during the initial filtration period; each time, the target pressure was reached sooner than during the previous interval. Volume filtered decreased from 0.9 to 0.03 m 3 /m 2 over the course of 14 processing hours. After the ninth backpulse, the backpulse frequency had become unsustainable, and it was decided to perform an extensive filter cleaning. The filter was cleaned by draining the chilled AP-107 feed into chilled holding containers, introducing 0.1 M NaOH into the feed vessel, and recirculating the NaOH through the system for 20 minutes before allowing the system to soak for 2 hours without temperature control. A measurable decrease in filter resistance during this recirculation indicated that the 0.1 M NaOH was likely dissolving some of the solids that had deposited on the filter. Post cleaning, the filter resistance was effectively restored to initial conditions as the initial transmembrane pressure was restored to original levels. However, resumed processing of the AP-107 feed at 16 °C continued to result in an increased rate of filter resistance. An additional five backpulses were conducted (four during feed processing, one during subsequent cleaning) before the conclusion of the test. Solids concentrated from the backpulse solutions displayed sodium oxalate-type phases, Al-oxides and sodium Al-oxides/carbonates, iron oxides, and Ca-bearing phases (calcite). The scanning electron microscopy analyses also revealed a large distribution of particles, with some particles, notably sodium phosphate dodecahydrate, having diameters close to 0.5 mm.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗