scholarly journals Determination of soil specific surface area by water vapor adsorption: II Dependence of soil specific surface area on clay and organic carbon content

1987 ◽  
Vol 59 (2) ◽  
pp. 67-72
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Water Vapor ◽  
Organic Carbon ◽  
Specific Surface ◽  
Carbon Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mineral Soil ◽  
Water Vapor Adsorption ◽  
Organic Carbon Content ◽  
Vapor Adsorption

The specific surface area of 60 mineral soil samples estimated by water vapor adsorption at 20 % relative humidity ranged from 12.1 ± 3.6 to 225.1 ±18.4 m2/g. Clay (range 1—72 %) and organic carbon content (0.7—14.6 %) together explained 84 % of the variation in the surface area. The regression equation predicting the specific surface area of soil was surface area (m2/g) =2.69+ 1.23clay-% +8.69org.C-%.

scholarly journals Water Vapor Adsorption Capacity of Thermally Fluorinated Carbon Molecular Sieves for CO2Capture

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jin-Young Jung ◽  
Hye-Ryeon Yu ◽  
Se Jin In ◽  
Young Chul Choi ◽  
Young-Seak Lee
Keyword(s):  
Water Vapor ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Molecular Sieves ◽  
Total Pore Volume ◽  
Water Vapor Adsorption ◽  
Carbon Molecular Sieves ◽  
Vapor Adsorption

The surfaces of carbon molecular sieves (CMSs) were thermally fluorinated to adsorb water vapor. The fluorination of the CMSs was performed at various temperatures (100, 200, 300, and 400°C) to investigate the effects of the fluorine gas (F2) content on the surface properties. Fluorine-related functional groups formed were effectively generated on the surface of the CMSs via thermal fluorination process, and the total pore volume and specific surface area of the pores in the CMSs increased during the thermal fluorination process, especially those with diameters ≤ 8 Å. The water vapor adsorption capacity of the thermally fluorinated CMSs increased compared with the as-received CMSs, which is attributable to the increased specific surface area and to the semicovalent bonds of the C–F groups.

scholarly journals Preparation and water vapor adsorption of “green” walnut-shell activated carbon by CO2 physical activation

2020 ◽  
Vol 38 (1-2) ◽  
pp. 60-76 ◽  
Author(s):  
Hong Zhao ◽  
Qiongfen Yu ◽  
Ming Li ◽  
Shengnan Sun
Keyword(s):  
Activated Carbon ◽  
Water Vapor ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Water Vapor Adsorption ◽  
Walnut Shell ◽  
Physical Activation ◽  
Vapor Adsorption

In this study, activated carbons without any chemical residue were prepared from walnut shells. The preparation method in a tube furnace included a pyrolysis carbonization process and a CO2 activation process. The influences of activation temperature and holding time on the specific surface area, yield, and pore structure were investigated. Adsorption performance of water vapor was also examined in details. Thermogravimetric analysis, N2 adsorption–desorption isotherm, and scanning electron microscope were used to characterize samples. The result shows that the activation energy at different heating rates varies from 30.16 to 64.86 kJ/mol. The highest water vapor adsorption capacity of the sample is 0.3824 g/g and it takes only 30 min to realize regeneration. And the maximum Brunauer–Emmett–Teller specific surface area of 1228 m2/g also occurs in this optimal preparation condition. CO2 physical activation method was found to have a positive effect on pore structure development of activated carbon for water vapor adsorption.

scholarly journals Determination of soil specific surface area by water vapor adsorption: I Drying of soil samples

1987 ◽  
Vol 59 (2) ◽  
pp. 63-65
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Mineral Soil ◽  
Clay Content ◽  
Fine Sand ◽  
Water Vapor Adsorption ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Clay Sample

Drying of three mineral soil samples (clay content 4—58 %, organic carbon content 1—5 %) equilibrated at 75.5 % relative humidity was studied. The soils were dried in an oven at +50°C, +70°C and + 105°C for 4 and 8 hours and in a desiccator over pure concentrated H2SO4 and P2O5. Drying over desiccants for 8 hours removed less water than drying at + 50°C. Drying over desiccants for 3—7 days was as efficient as drying at +70°C, for 14—24 days as efficient as 4 hours of drying at + 105°C. Eight hours of drying at + 105°C seemed to be too drastic, because it caused a greater weight loss in the clay sample of 5 % organic carbon content than did prolonged desiccant-drying. Drying at + 70°Cremoved as much water from fine sand which contained 4 % clay as prolonged desiccant-drying.

scholarly journals Experimental Study on Activated Carbon-MIL-101(Cr) Composites for Ethanol Vapor Adsorption

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3811
Author(s):  
Zhongbao Liu ◽  
Jiayang Gao ◽  
Xin Qi ◽  
Zhi Zhao ◽  
Han Sun
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ethanol Vapor ◽  
Future Application ◽  
Working Fluid ◽  
Relative Pressure ◽  
Adsorption Refrigeration ◽  
Vapor Adsorption

In this study, the hydrothermal method was used to synthesize MIL-101(Cr), and activated carbon (AC) with different content was incorporated in to MIL-101(Cr), thereby obtaining AC-MIL-101(Cr) composite material with a huge specific surface area. The physical properties of MIL-101(Cr) and AC-MIL-101(Cr) were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), nitrogen adsorption and desorption and specific surface area testing, and ethanol vapor adsorption performance testing. The results show that with the increase of activated carbon content, the thermal stability of AC-MIL-101(Cr) is improved. Compared with the pure sample, the BET specific surface area and pore volume of AC-MIL-101(Cr) have increased; In the relative pressure range of 0–0.4, the saturated adsorption capacity of AC-MIL-101(Cr) to ethanol vapor decreases slightly. It is lower than MIL-101(Cr), but its adsorption rate is improved. Therefore, AC-MIL-101(Cr)/ethanol vapor has a good application prospect in adsorption refrigeration systems. The exploration of AC-MIL-101(Cr) composite materials in this paper provides a reference for the future application of carbon-based/MOFS composite adsorbent/ethanol vapor working fluid in adsorption refrigeration.

scholarly journals Impact of Biochar on Physicochemical Properties of Haplic Luvisol Soil under Different Land Use: A Plot Experiment

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 531 ◽  
Author(s):  
Marta Cybulak ◽  
Zofia Sokołowska ◽  
Patrycja Boguta
Keyword(s):  
Physicochemical Properties ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Physicochemical Characterization ◽  
Organic Carbon Content ◽  
Limited Information ◽  
Opposite Trend ◽  
And Function ◽  
Positive Effect

There is limited information regarding the effect of biochar (BioC) on improving the fertility of degraded soils (fallow and grassland), particularly with respect to changes with time. The objective of the study was to evaluate, in a three-year field experiment, the influence of BioC on the physicochemical properties of Haplic Luvisol. BioC, obtained via wood waste pyrolysis at 650 °C, was applied to the soil of subplots under fallow and grassland at rates of 0, 1, 2, and 3 kg·m−2. Soil samples were collected eight times, from 2013 to 2015. Physicochemical characterization was performed for soil and BioC by analyzing density, pH, surface charge, as well as ash and organic carbon content. BioC’s influence on the physicochemical properties of degraded soils was determined by analyzing the changes in pH, specific surface area, radius, and volume of the micropore. The addition of BioC affected analyzed soils to varying degrees. In the case of the fallow, a positive effect on changes in these parameters was observed, particularly at the highest biochar dose and for the last year of the experiment. However, for the grassland, in most cases we observed the opposite trend—for example, pH and specific surface area values decreased with increasing biochar dose. We believe that it is necessary to examine how BioC affects sorption properties of organic matter of fallow and grassland soils, as well as the BioC’s influence on humic acids of these soils as a function on BioC dose and function of time.

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