RELATIONSHIPS OF SPECIFIC SURFACE AREA AND CLAY CONTENT TO SHRINK-SWELL POTENTIAL OF SOILS HAVING DIFFERENT CLAY MINERALOGICAL COMPOSITIONS

1978 ◽  
Vol 58 (2) ◽  
pp. 159-166 ◽  
Author(s):  
G. J. ROSS
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Clay Mineralogy ◽  
Clay Content ◽  
Surface Areas ◽  
Swell Potential ◽  
Close Relationship ◽  
Highly Correlated ◽  
Mineralogical Compositions

Data for 22 samples from 17 pedons were analyzed for relationships of specific surface area and amounts and kinds of clay to coefficient of linear extensibility, as determined by the paste method (COLErod), and to free swelling index (FSI). The soils were divided into three main groups according to their clay mineralogy. The clay of the first group was micaceous, that of the second group kaolinitic, and that of the third group montmorillonitic. Both clay contents and specific surface areas of the combined first and second groups of soils were closely related to COLErod (r2 = 0.81 and r2 = 0.91) with specific surface area giving the higher correlation. The correlation of clay content with COLErod decreased markedly, however, when the montmorillonitic soils were included (r2 = 0.56). In contrast, the correlation of specific surface area with COLErod remained high (r2 = 0.97), indicating that for the soils used in this study, specific surface area was more basic with respect to shrink–swell potential than was clay content. Specific surface area was also highly correlated with FSI (r2 = 0.96) which was expected from the close relationship between COLErod and FSI (r2 = 0.95).

Chemical EOR in Low Permeability Sandstone Reservoirs: Impact of Clay Content on the Transport of Polymer and Surfactant

2021 ◽  
Author(s):  
Imane Guetni ◽  
Claire Marlière ◽  
David Rousseau
Keyword(s):  
Porous Media ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Clay Content ◽  
Low Permeability ◽  
Depth Propagation ◽  
The Impact ◽  
Polymer Retention ◽  
Injection Strategies

Abstract Application of chemical enhanced oil recovery (C-EOR) processes to low-permeability sandstone reservoirs (in the 10-100 mD range) can be very challenging as strong retention and difficult in-depth propagation of polymer and surfactant can occur. Transport properties of C-EOR chemicals are particularly related to porous media mineralogy (clay content). The present experimental study aimed at identifying base mechanisms and providing general recommendations to design economically viable C-EOR injection strategies in low permeability clayey reservoirs. Polymer and surfactant injection corefloods were conducted using granular packs (quartz and clay mixtures) with similar petrophysical characteristics (permeability 70-130 mD) but having various mineralogical compositions (pure quartz sand, sand with 8 wt-% kaolinite and sand with 8 wt-% smectite). The granular packs were carefully characterized in terms of structure (SEM) and specific surface area (BET). The main observables from the coreflood tests were the resistance and residual resistance factors generated during the chemical injections, the irreversible polymer retention and the surfactant retention in various injection scenarios (polymer alone, surfactant alone, polymer and surfactant). A first, the impact of the clay contents on the retention of polymer and surfactant considered independently was examined. Coreflood results have shown that retention per unit mass of rock strongly increased in presence of both kaolinite and smectite, but not in the same way for both chemicals. For polymer, retention was about twice higher with kaolinite than with smectite, despite the fact that the measured specific surface area of the kaolinite was about 5 times less than that of the smectite. Conversely, for surfactant, retention was much higher with smectite than with kaolinite. Secondly, the impact of the presence of surfactant on the polymer in-depth propagation and retention was investigated in pure quartz and kaolinite-bearing porous media. In both mineralogies, the resistance factor quickly stabilized when polymer was injected alone whereas injection of larger solution volumes was required to reach stabilization when surfactant was present. In pure quartz, polymer retention was shown, surprisingly, to be one order of magnitude higher in presence of surfactant whereas with kaolinite, surfactant did not impact polymer retention. The results can be interpreted by considering adsorption-governed retention. The mechanistic pictures being that (a) large polymer macromolecules are not able to penetrate the porosity of smectite aggregates, whereas surfactant molecules can, and (b) that surfactant and polymer mixed adsorbed layers can be formed on surfaces with limited affinity for polymer. Overall, this study shows that C-EOR can be applied in low permeability reservoirs but that successful injection strategies will strongly depend on mineralogy.

Nanoporous zero-valent iron

2005 ◽  
Vol 20 (12) ◽  
pp. 3238-3243 ◽  
Author(s):  
Jiasheng Cao ◽  
Patrick Clasen ◽  
Wei-xian Zhang
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Performance Enhancement ◽  
Zero Valent Iron ◽  
Iron Particles ◽  
Surface Areas ◽  
Batch Tests ◽  
Resin Beads ◽  
Solid Iron

Hollow and nanoporous particles of zero-valent iron (ZVI) were prepared with template-directed synthesis. Polymer resin beads (0.4 mm diameter) were coated with nanoscale iron particles by reductive precipitation of ferrous iron [Fe(II)] with sodium borohydride. The resin was calcinated at 400 °C to produce hollow and nanoporous iron spheres. The nanoporous iron oxides were then reduced to metallic iron by hydrogen at 500 °C. Scanning electron microscope images of the reduced iron spheres showed that the particles were hollow. The shell thickness was approximately 5 μm and highly porous. Brunauer–Emmett–Teller specific surface area was 2100 m2/kg. In comparison, the theoretical specific surface area of solid iron particles of the same size is just 1.9 m2/kg. Batch tests showed that the surface area normalized reactivity of the porous particles were 14–31% higher than microscale iron particles with similar surface areas for the transformation of hexavalent chromium [Cr(VI)], azo dye Orange II {4-[(2-hydroxyl-1-naphthalenyl)azo]-benzenesulfonic acid monosodium}, and trichloroethene. The combined performance enhancement (larger surface area and higher surface activity) is significant (>1200 times).

Effect of ZnO Particle Size on the Curing of Carboxylated NBR and Carboxylated SBR

2004 ◽  
Vol 77 (2) ◽  
pp. 214-226 ◽  
Author(s):  
G. R. Hamed ◽  
K.-C. Hua
Keyword(s):  
Zinc Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cure Rate ◽  
Surface Areas ◽  
Diffusion Limited ◽  
Rate Of Dissolution ◽  
Oxide Particles ◽  
And Diffusion

Abstract A carboxylated nitrile rubber (XNBR) and a carboxylated SBR (XSBR) were mixed with zinc oxide particles of different specific surface areas (“S”, 35 m2/g; “M”, 3.5m2/g; “L”, 0.5 m2/g) and cure behavior at 165 ºC studied using oscillating disc rheometry. Without added zinc oxide, both raw rubbers slowly stiffen over many hours of heating. This is probably due to condensation of carboxyl groups to form anhydride crosslinks. XNBR compositions containing the finely divided “S” crosslink much more rapidly. Full cure is reached after about 10 minutes of heating. Cure rate decreases markedly as the specific surface area of the ZnO decreases. A composition containing “M” at twice stoichiometry requires about an hour to cure well, while with “L”, about 10 hours are required. In contrast, curing of the XSBR depends little on the specific surface area of the ZnO, either with “S” or “L”, curing is essentially complete after 30 minutes. After simply mixing ZnO into either rubber, it remains as a dispersed particulate. With XNBR, curing appears to be controlled by the rate of dissolution and diffusion of ZnO, while, with XSBR, reaction is not diffusion limited and may be confined to regions near particle surfaces.

A Comparison of Methods for Determining Surface Areas of Carbon Black

1973 ◽  
Vol 46 (1) ◽  
pp. 192-203 ◽  
Author(s):  
R. A. Klyne ◽  
B. D. Simpson ◽  
M. L. Studebaker
Keyword(s):  
Carbon Black ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Surface Areas ◽  
Furnace Black ◽  
Area Increase ◽  
Experimental Errors ◽  
Specific Surface Areas ◽  
Surface Area Increase

Abstract 1. The various tint tests correlate with each other—it does not make much difference which of the three procedures is used. The discrimination between similar blacks is comparable. Specific surface areas obtained by the three methods are comparable and differences appear to be due to experimental errors. (Compare Figures 5–7). 2. Surface areas larger than some 90 to 100 m2/g cannot be reliably determined from tint strength measurements alone. 3. Structure exerts a pronounced effect on tint strength of furnace blacks, especially above 90 to 100 m2/g. Porosity and/or composition are apparently also variables which affect tinting strength. 4. Densichron reflectance on the dry carbon black can be used to estimate specific surface areas up to about 140 m2/g; but, since theabsoluteerrorincreases as the specific surface area increases, this method loses some of its reliability at values above about 110 m2/g. The relative error in reflectance determinations does not vary greatly over the furnace-black range. Densichron reflectance is influenced by composition, evidently due to composition-related differences in optical properties of the carbons. 5. In CTAB adsorption measurements, titration errors and handling errors tend to be rather constant for blacks of different surface area. Hence, CTAB permits better discrimination among blacks of small particle size. 6. The errors in Densichron reflectance surface area increase with specific surface area. Hence, the deviations between CTAB and reflectance surface area which are due to experimental error increase with the surface area of the sample.

Binding of water-extractable organic carbon to clay subsoil: effects of clay subsoil properties

Soil Research ◽  
2015 ◽  
Vol 53 (1) ◽  
pp. 81 ◽  
Author(s):  
Shinhuey Lim ◽  
Trung-Ta Nguyen ◽  
Petra Marschner
Keyword(s):  
Organic Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sandy Soils ◽  
Clay Content ◽  
Sodium Absorption ◽  
Oxide Content ◽  
Relative Importance ◽  
Water Extractable

Addition of clay-rich subsoils to sandy soils can increase yield and may increase organic carbon (OC) retention in soils. The ability of clays to bind OC is likely to be influenced by clay properties, but little is known about the relative importance of properties of clay subsoils for binding of OC. A batch sorption experiment was conducted using seven clay subsoils collected from agricultural lands where claying was carried out. Clay subsoils were shaken for 17 h at 4°C with different concentrations of water-extractable OC (WEOC: 0, 2.5, 5.0, 7.5, and 9.0 g kg–1 soil) derived from mature wheat (Triticum aestivum L.) straw at a 1 : 10 soil : extract ratio. Sorption of WEOC was positively correlated with clay content, specific surface area and concentration of iron oxides. Further, WEOC sorption was negatively correlated with total OC content, sodium absorption ratio and cation ratio of soil structural stability. However, the relative importance of these properties for WEOC sorption differed among soils. In conclusion, OC retention in clay-amended sandy soils will be positively related to clay soil properties such as clay and Fe oxide content and specific surface area.

scholarly journals A Case Study of Waste Scrap Tyre-Derived Carbon Black Tested for Nitrogen, Carbon Dioxide, and Cyclohexane Adsorption

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4445 ◽  
Author(s):  
Zuzana Jankovská ◽  
Marek Večeř ◽  
Ivan Koutník ◽  
Lenka Matějová
Keyword(s):  
Activated Carbon ◽  
Carbon Black ◽  
Specific Surface ◽  
Surface Area ◽  
Sorption Capacity ◽  
Specific Surface Area ◽  
Textural Properties ◽  
Pyrolytic Carbon ◽  
Surface Areas ◽  
Wide Range

Waste scrap tyres were thermally decomposed at the temperature of 600 °C and heating rate of 10 °C·min−1. Decomposition was followed by the TG analysis. The resulting pyrolytic carbon black was chemically activated by a KOH solution at 800 °C. Activated and non-activated carbon black were investigated using high pressure thermogravimetry, where adsorption isotherms of N2, CO2, and cyclohexane were determined. Isotherms were determined over a wide range of pressure, 0.03–4.5 MPa for N2 and 0.03–2 MPa for CO2. In non-activated carbon black, for the same pressure and temperature, a five times greater gas uptake of CO2 than N2 was determined. Contrary to non-activated carbon black, activated carbon black showed improved textural properties with a well-developed irregular mesoporous-macroporous structure with a significant amount of micropores. The sorption capacity of pyrolytic carbon black was also increased by activation. The uptake of CO2 was three times and for cyclohexane ten times higher in activated carbon black than in the non-activated one. Specific surface areas evaluated from linearized forms of Langmuir isotherm and the BET isotherm revealed that for both methods, the values are comparable for non-activated carbon black measured by CO2 and for activated carbon black measured by cyclohexane. It was found out that the N2 sorption capacity of carbon black depends only on its specific surface area size, contrary to CO2 sorption capacity, which is affected by both the size of specific surface area and the nature of carbon black.

Experimental Studies of Carbon Electrodes With Various Surface Area for Li–O2 Batteries

2019 ◽  
Vol 16 (4) ◽  
Author(s):  
Fangzhou Wang ◽  
P. K. Kahol ◽  
Ram Gupta ◽  
Xianglin Li
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Discharge Capacity ◽  
Carbon Materials ◽  
High Specific Surface Area ◽  
Acetylene Black ◽  
Carbon Electrodes ◽  
Tea Leaves ◽  
Surface Areas

Li−O2 batteries with carbon electrodes made from three commercial carbons and carbon made from waste tea leaves are investigated in this study. The waste tea leaves are recycled from household tea leaves and activated using KOH. The carbon materials have various specific surface areas, and porous structures are characterized by the N2 adsorption/desorption. Vulcan XC 72 carbon shows a higher specific surface area (264.1 m2/g) than the acetylene black (76.5 m2/g) and Super P (60.9 m2/g). The activated tea leaves have an extremely high specific surface area of 2868.4 m2/g. First, we find that the commercial carbons achieve similar discharge capacities of ∼2.50 Ah/g at 0.5 mA/cm2. The micropores in carbon materials result in a high specific surface area but cannot help to achieve higher discharge capacity because it cannot accommodate the solid discharge product (Li2O2). Mixing the acetylene black and the Vulcan XC 72 improves the discharge capacity due to the optimized porous structure. The discharge capacity increases by 42% (from 2.73 ± 0.46 to 3.88 ± 0.22 Ah/g) at 0.5 mA/cm2 when the mass fraction of Vulcan XC 72 changes from 0 to 0.3. Second, the electrode made from activated tea leaves is demonstrated for the first time in Li−O2 batteries. Mixtures of activated tea leaves and acetylene black confirm that mixtures of carbon material with different specific surface areas can increase the discharge capacity. Moreover, carbon made from recycled tea leaves can reduce the cost of the electrode, making electrodes more economically achievable. This study practically enhances the discharge capacity of Li−O2 batteries using mixed carbons and provides a method for fabricating carbon electrodes with lower cost and better environmental friendliness.

Valorization of cellulose-doped lignin: application of cellulose-doped lignin-derived activated carbon in capacitors and investigation of its textural properties and electrochemical performance

2021 ◽  
Author(s):  
Liangcai Wang ◽  
Xin Feng ◽  
Huanhuan Ma ◽  
Jielong Wu ◽  
Yu Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Wall Thickness ◽  
Textural Properties ◽  
Pore Wall ◽  
Surface Areas ◽  
Pore Wall Thickness

Abstract This work provides an idea for efficient and harmless utilization of lignin and further evaluated the textural properties of lignin-derived activated carbon/specific capacitance relationship. The yield of cellulose-doped apricot shell lignin (ASLC) was 30.42%. H3PO4/KOH was used to assist the preparation of ASLC-derived activated carbon (AAC) for capacitors. The specific surface areas of the as-obtained AAC-P-3 and AAC-K-2 were 1475.16 m2/g and 2136.56 m2/g, respectively. The specific capacitances of AAC-P-3 and AAC-K-2 were 169.14 F/g and 236.00 F/g, respectively, upon the current density of 0.50 A/g. In capacitors containing aqueous KOH as the electrolyte, the AR2 (0.983) between specific surface area and specific capacitance was highest, followed by the AR2 (0.978) between Vmicro/Vmeso and specific capacitance, the AR2 (0.975) between pore-wall thickness and specific capacitance. Consequently, the specific capacitances of the AACs depend not only the specific surface area, but also on the Vmicro/Vmeso, pore-wall thickness, and Vmicro.

Comparison of three methods of measuring surface area of soils

1999 ◽  
Vol 79 (2) ◽  
pp. 345-351 ◽  
Author(s):  
E. de Jong
Keyword(s):  
Organic Matter ◽  
Surface Area ◽  
External Surface ◽  
Clay Mineralogy ◽  
Clay Content ◽  
Sorptive Capacity ◽  
Measuring Surface ◽  
Glycol Monoethyl Ether ◽  
Highly Correlated ◽  
The Impact

Surface area (SA) is an important property of soils, but different methods can give widely different estimates of SA, and of the contribution of organic matter to SA. This study was undertaken to compare two common methods of measuring SA (EGME [ethylene glycol monoethyl ether] and N2 sorption) with SA estimates using H2O sorption on selected Saskatchewan soils; some soils from Kenya were included to show the impact of clay mineralogy. For the Saskatchewan soils, the three estimates of SA were highly correlated to each other and to clay content, but SA EGME was 2 to 3 times SA H2O and 7 to 52 times SA N2. Organic matter did not appear to contribute to SA EGME, increased SA H2O and decreased SA N2. Clearly the three methods differ in their access to internal and external surface area and this should affect their utility as indices of the sorptive capacity of field soils. Key words: Surface area, EGME, N2 sorption, water sorption

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