scholarly journals Sorption of CO2 and CH4 on Raw and Calcined Halloysite—Structural and Pore Characterization Study

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 917 ◽  
Author(s):  
Anna Pajdak ◽  
Norbert Skoczylas ◽  
Arkadiusz Szymanek ◽  
Marcin Lutyński ◽  
Piotr Sakiewicz
Keyword(s):  
Surface Area ◽  
Structural Parameters ◽  
Mercury Porosimetry ◽  
Effective Diffusion ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
High Rate ◽  
Co2 Sorption

The article presents comparative characteristics of the pore structure and sorption properties of raw halloysite (R-HAL) and after calcination (C-HAL) at the temperature of 873 K. Structural parameters were determined by optical scanning and transmission electron microscopy methods as well as by mercury porosimetry (MIP, Hg) and low-pressure nitrogen adsorption (LPNA, N2, 77 K). The surface area parameter (LPNA) of halloysite mesopores before calcination was 54–61 m2/g. Calcining caused the pore surface to develop to 70–73 m2/g. The porosity (MIP) of halloysite after calcination increased from 29% to 46%, while the surface area within macropores increased from 43 m2/g to 54 m2/g. The total pore volume within mesopores and macropores increased almost twice after calcination. The course of CH4 and CO2 sorption on the halloysite was examined and sorption isotherms (0–1.5 MPa, 313 K) were determined by gravimetric method. The values of equilibrium sorption capacities increased at higher pressures. The sorption capacity of CH4 in R-HAL was 0.18 mmol/g, while in C-HAL 0.21 mmol/g. CO2 sorption capacities were 0.54 mmol/g and 0.63 mmol/g, respectively. Halloysite had a very high rate of sorption equilibrium. The values of the effective diffusion coefficient for methane on the tested halloysite were higher than De > 4.2 × 10−7 cm2/s while for carbon dioxide De > 3.1 × 10−7 cm2/s.

scholarly journals Nanometer Pore Structure Characterization of Taiyuan Formation Shale in the Lin-Xing Area Based on Nitrogen Adsorption Experiments

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Chenlong Ding ◽  
Jinxian He ◽  
Hongchen Wu ◽  
Xiaoli Zhang
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Shale Gas ◽  
Pore Volume ◽  
Ordos Basin ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Taiyuan Formation

Ordos Basin is an important continental shale gas exploration site in China. The micropore structure of the shale reservoir is of great importance for shale gas evaluation. The Taiyuan Formation of the lower Permian is the main exploration interval for this area. To examine the nanometer pore structures in the Taiyuan Formation shale reservoirs in the Lin-Xing area, Northern Shaanxi, the microscopic pore structure characteristics were analyzed via nitrogen adsorption experiments. The pore structure parameters, such as specific surface area, pore volume, and aperture distribution, of shale were calculated; the significance of the pore structure for shale gas storage was analyzed; and the main controlling factors of pore development were assessed. The results indicated the surface area and hole volume of the shale sample to be 0.141–2.188 m2/g and 0.001398–0.008718 cm3/g, respectively. According to the IUPAC (International Union of Pure and Applied Chemistry) classification, mesopores and macropores were dominant in the pore structure, with the presence of a certain number of micropores. The adsorption curves were similar to the standard IV (a)-type isotherm line, and the hysteresis loop type was mainly similar to H3 and H4 types, indicating that most pores are dominated by open type pores, such as parallel plate-shaped pores and wedge-shaped slit pores. The micropores and mesopores provide the vast majority of the specific surface area, functioning as the main area for the adsorption of gas in the shale. The mesopores and macropores provide the vast majority of the pore volume, functioning as the main storage areas for the gas in the shale. Total organic carbon had no notable linear correlation with the total pore volume and the specific surface area. Vitrinite reflectance (Ro) had no notable correlation with the specific surface area, but did have a low “U” curve correlation with the total pore volume. There was no relationship between the quartz content and specific surface area and total pore volume. In addition, there was no notable correlation between the clay mineral content and total specific surface area and total pore volume.

scholarly journals Structural and fractal characterization of adsorption pores of middle–high rank coal reservoirs in western Yunnan and eastern Guizhou: An experimental study of coals from the Panguan syncline and Laochang anticline

2018 ◽  
Vol 37 (1) ◽  
pp. 251-272 ◽  
Author(s):  
Junjian Zhang ◽  
Chongtao Wei ◽  
Gaoyuan Yan ◽  
Guanwen Lu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pore Diameter ◽  
Structural Parameters ◽  
Total Pore Volume ◽  
Type A ◽  
Type B ◽  
Type C

To better understand the structural characteristic of adsorption pores (pore diameter < 100 nm) of coal reservoirs around the coalbed methane production areas of western Yunnan and eastern Guizhou, we analyzed the structural and fractal characteristics of pore size range of 0.40–2.0 nm and 2–100 nm in middle–high rank coals ( Ro,max = 0.93–3.20%) by combining low-temperature N2/CO2 adsorption tests and surface/volume fractal theory. The results show that the coal reservoirs can be divided into three categories: type A ( Ro,max < 2.15%), type B (2.15% <  Ro,max <2.50%), and type C ( Ro,max > 2.15%). The structural parameters of pores in the range from 2 to 100 nm are influenced by the degree of coal metamorphism and the compositional parameters (e.g., ash and volatile matter). The dominant diameters of the specific surface areas are 10–50 nm, 2–50 nm, and 2–10 nm, respectively. The pores in the range from <2 nm provide the largest proportion of total specific surface area (97.22%–99.96%) of the coal reservoir, and the CO2-specific surface area and CO2-total pore volume relationships show a positive linear correlation. The metamorphic degree has a much greater control on the pores (pore diameter less than 2 nm) structural parameters than those of the pore diameter ranges from 2 to 100 nm. Dv1 and Dv2 can characterize the structure of 2–100 nm adsorption pores, and Dv1 (volume heterogeneity) has a positive correlation with the pore structural parameters such as N2-specific surface area and N2-total pore volume. This parameter can be used to characterize volume heterogeneity of 2–10 nm pores. Dv2 (surface heterogeneity) showed type A > type B > type C and was mainly affected by the metamorphism degree. Ds2 can be used to characterize the pore surface heterogeneity of micropores in the range of 0.62–1.50 nm. This parameter has a good correlation with the pore parameters (CO2-total pore volume, CO2-specific surface area, and average pore size) and is expressed as type C < type B < type A. In conclusion, the heterogeneity of the micropores is less than that of the meso- and macropores (2–100 nm). Dv1, Dv2, and Ds2 can be used as effective parameters to characterize the pore structure of adsorption pores. This result can provide a theoretical basis for studying the pore structure compatibility of coal reservoirs in the region.

scholarly journals Textural properties of synthetic clay-ferrihydrite associations

Clay Minerals ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 395-407 ◽  
Author(s):  
R. Celis ◽  
J. Cornejo ◽  
M. C. Hermosin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mercury Porosimetry ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Fractal Approach ◽  
Adsorption Data ◽  
Synthetic Clay ◽  
Nitrogen Adsorption Data

AbstractKaolinite-ferrihydrite and montmorillonite-ferrihydrite associations were prepared following a procedure based on the Russell method for the synthesis of ferrihydrite and the texture of the clay-ferrihydrite complexes was studied using different techniques. The textural properties of kaolinite were little affected by the Fe association, showing only a slight increase in the specific surface area measured by nitrogen adsorption and a decrease in the largest pores (>10 µm), as measured by mercury porosimetry. In contrast, the nitrogen specific surface area of the montmorillonite complexes was much higher than that of the clay without Fe and the pore structure depended on the amounts of Fe in the complexes. Application of the fractal approach to nitrogen adsorption data indicated that the surface roughness (microporosity) was greater for the complexes prepared from diluted Fe(III) solutions, in agreement with the information obtained from classical interpretation of the adsorption isotherms (shape of the isotherms and t-plots).

scholarly journals Synthesis of Hydrophobic Mesoporous Material MFS and Its Adsorption Properties of Water Vapor

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Guotao Zhao ◽  
Zhenxiao Zhao ◽  
Junliang Wu ◽  
Daiqi Ye
Keyword(s):  
Water Vapor ◽  
Surface Area ◽  
Mesoporous Material ◽  
High Surface ◽  
Synthesis Method ◽  
Gravimetric Method ◽  
Total Pore Volume ◽  
Adsorption Properties ◽  
Bet Surface Area ◽  
Mcm 41

Fluorine-containing hydrophobic mesoporous material (MFS) with high surface area is successfully synthesized with hydrothermal synthesis method by using a perfluorinated surfactant SURFLON S-386 template. The adsorption properties of water vapor on the synthesized MFS are also investigated by using gravimetric method. Results show that SEM image of the MFS depicted roundish morphology with the average crystal size of 1-2 μm. The BET surface area and total pore volume of the MFS are 865.4 m2 g−1and 0.74 cm3 g−1with a narrow pore size distribution at 4.9 nm. The amount of water vapor on the MFS is about 0.41 mmol g−1at 303 K, which is only 52.6% and 55.4% of MCM-41 and SBA-15 under the similar conditions, separately. The isosteric adsorption heat of water on the MFS is gradually about 27.0–19.8 kJ mol−1, which decreases as the absorbed water vapor amount increases. The value is much smaller than that on MCM-41 and SBA-15. Therefore, the MFS shows more hydrophobic surface properties than the MCM-41 and SBA-15. It may be a kind of good candidate for adsorption of large molecule and catalyst carrier with high moisture resistance.

scholarly journals Study on the Effects of Physical Properties of Tenera Palm Kernel during Drying and Its Moisture Sorption Isotherms

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1658
Author(s):  
Mina Habibiasr ◽  
Mohd Noriznan Mokhtar ◽  
Mohd Nordin Ibrahim ◽  
Khairul Faezah Md Yunos ◽  
Nuzul Amri Ibrahim
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Surface Area ◽  
Palm Kernel ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Kernel Length ◽  
Moisture Sorption Isotherms ◽  
Ground Kernel

A study on the effect of the physical properties and moisture sorption isotherm of palm kernels constitutes the critical criteria in evaluating the drying performance. The drying was evaluated as a function of moisture content (MC) in the range of 0.31–0.02 kg/kg (d.b.). Whereas, the equilibrium moisture content (EMC) of palm kernels (whole kernel and ground kernel) was determined experimentally using the standard gravimetric method at different temperatures (50 °C to 80 °C), over a range of relative humidity (RH) from 10% to 81%. Palm kernel length, width, and thickness decrease from 16.08 ± 2.09 mm to 14.17 ± 2.30 mm, 12.06 ± 1.40 mm to 11.24 ± 1.08 mm, and 10.01 ± 1.27 mm to 9.18 ± 1.04 mm, respectively, when MC decreased. Bulk density, surface area, and specific surface area decreased as the MC decreased, while porosity and true density were increased. EMC of palm kernels (whole kernel and ground kernel) decreased with an increase in temperature at constant RH. Modified Oswin and modified Halsey models were found to be the best for predicting desorption moisture isotherms for whole and ground palm kernel, respectively. Therefore, the study of the effect of drying on physical aspects as well as moisture sorption isotherms is important to further analyze the drying performance of Tenera palm kernel (e.g., equipment design and energy requirement).

Experimental Study on Coal Pore Characteristic Based on Cryogenic Liquid Nitrogen Method

2013 ◽  
Vol 341-342 ◽  
pp. 345-350 ◽  
Author(s):  
Wei Min Cheng ◽  
Xiao Qiang Zhang ◽  
Rui Zhang ◽  
Gang Wang
Keyword(s):  
Pore Structure ◽  
Surface Area ◽  
Liquid Nitrogen ◽  
Pore Volume ◽  
Single Point ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Cryogenic Liquid ◽  
Adsorption Method ◽  
Point Total

In view of pore distribution in coal, this paper applies BJH method that is based on the cylinder theory and adopts cryogenic liquid nitrogen adsorption method to carry out experimental investigation on pore structure of No.3U coal seam in Sanhekou Coalmine, obtaining the fact that pore structure of No.3U coal is complicated, the cool pores are mostly flask pores, others are the parallel plate pores with one end closed and the cylinder pores with one end closed; According to the distribution of BJH pore volume and pore surface area, ultramicropores with apertures less than 10 nm are among the most; Then obtain the average BET specific surface area, the distribution of BJH pore volume and pore area, average single-point total pore volume and most probable pore .etc, which conducive to a better understanding of the micropores characteristic of coal.

scholarly journals Surface Characteristics of Hardened Slag–Lime Pastes

1995 ◽  
Vol 12 (4) ◽  
pp. 323-334 ◽  
Author(s):  
Anwar Amin
Keyword(s):  
Surface Area ◽  
Chemical Nature ◽  
Weight Ratio ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Surface Characteristics ◽  
Hydraulic Radius ◽  
Initial Water ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Two types of slag–lime pastes were prepared from granulated blast furnace slag and calcium hydroxide in a weight ratio of 80:20 and using initial water/solid (W/C) ratios of 0.25 and 0.4, respectively, to produce low and normal porosity pastes. After being hydrated for various lengths of time, the pastes were examined for surface area and pore structure using the nitrogen adsorption technique. The results of surface area, total pore volume and mean hydraulic radius measurements were related as far as possible to the chemical nature and physical state of the hydration products formed.

scholarly journals Characterization of Metal-Impregnated Charcoal: Nitrogen Adsorption

1995 ◽  
Vol 12 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Riaz Qadeer ◽  
Javed Hanif ◽  
Abdul Majeed
Keyword(s):  
Surface Area ◽  
Pore Volume ◽  
Continuous Flow ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Ionic Radii ◽  
Sorption System ◽  
Metal Impregnation ◽  
Continuous Flow Method

Nitrogen adsorption on metal (Ni, Cu, Zn) impregnated charcoal has been carried out at 77 K by the continuous flow method using a Quantasorb sorption system. It was observed that such metal impregnation did not contribute any extra surface area to the charcoal. The values of the surface area, micropore and total pore volumes determined from nitrogen adsorption follow the sequence Ni–charcoal < Cu–charcoal < Zn–charcoal < charcoal. Their behaviour is discussed in terms of the ionic radii of the metal ions concerned. The pore size distribution curves demonstrate the microporous nature of the charcoal, with the micropores contributing significantly to the total pore volume.

scholarly journals Heterogeneity Characteristics of Lacustrine Shale Oil Reservoir Under the Control of Lithofacies: A Case Study of the Dongyuemiao Member of Jurassic Ziliujing Formation, Sichuan Basin

2021 ◽  
Vol 9 ◽  
Author(s):  
Peng Li ◽  
Zhongbao Liu ◽  
Haikuan Nie ◽  
Xinping Liang ◽  
Qianwen Li ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Clay Minerals ◽  
Specific Surface Area ◽  
Sichuan Basin ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Hydrocarbon Generation ◽  
Shale Oil ◽  
Lacustrine Shale

The lacustrine shale in the Dongyuemiao Member of the Fuling area, Sichuan Basin, is widely distributed and has huge shale oil resource potential. It is one of the important replacement areas for shale oil exploration in China. To investigate the key shale oil evaluation well, Well FY10, in the Fuling area, X-ray diffraction (XRD) mineral analysis, Rock-Eval, argon ion polishing-scanning electron microscope (SEM), Mercury injection capillary pressure (MICP), and low pressure nitrogen adsorption were launched to determine the heterogeneity of the pore system in the lacustrine shale of the Dongyuemiao Member. The mineral composition exhibits a high degree of heterogeneity, and the shale can be divided into two main lithofacies: argillaceous shale and mixed shale. The porosity ranges from 2.95 to 8.43%, and the permeability ranges from 0.05 to 1.07 × 10−3 μm2. The physical properties of mixed shale are obviously better than those of argillaceous shale. Inorganic mineral pores, such as linear pores between clay minerals and calcite dissolution pores, are mainly developed, while a small amount of organic pores can be observed. The average total pore volume (Vp) is 0.038 ml/g with an average specific surface area of 5.38 m2/g. Mesopores provide the main Vp (average 61.72%), and micropores provide mostly specific surface area. TOC imposes a strong controlling effect on the development of micropores. Clay minerals are the main contributors to mesopores and macropores. The organic-inorganic interaction during the process of diagenesis and hydrocarbon generation controls the formation of shale pore systems.

Sorption Hysteresis Characterization of CH4 and CO2 on Anthracite, Bituminous Coal, and Lignite at Low Pressure

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Zhenjian Liu ◽  
Zhenyu Zhang ◽  
Yiyu Lu ◽  
Sing Ki Choi ◽  
Xiaoqian Liu
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Bituminous Coal ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Low Pressure ◽  
Wide Distribution ◽  
Co2 Sorption ◽  
Sorption Hysteresis

Sorption hysteresis characterization of CH4 and CO2 on lignite, bituminous coal, and anthracite were studied to improve the understanding of the interaction between gas molecules and different ranks of coal and further improve the precision of the adsorption methods in characterizing pore structure at low pressure. Pore structure of three ranks of coal was investigated with scanning electron microscopy (SEM) and nitrogen (N2) adsorption. Then, CH4 and CO2 sorption isotherms were measured using the gravimetric method under 288, 308, and 328 K. The N2 sorption isotherms show that a wide distribution of pore size existed in three coal samples, and with the process of coalification, the specific surface area (SSA) decreased and then increased, while the pore size of coal monotonically decreased. This is confirmed by SEM observation. The measured sorption isotherms were then decomposed into simultaneously running adsorption and absorption branches based on the assumption that the former is totally reversible and the latter completely irreversible. The reconstructed adsorption branches can be well described by both Langmuir model and Dubinin–Radushkevich (D–R) equation. The absorption, which represents the sorption hysteresis portion, increased with pressure, but decreased with temperature. The absorbed amount of gas increased with pressure, but the absorption of CO2 increased concavely with gas pressure while CH4 followed an upward exponential function. Also, the absorption varied with coal rank, following a U-shaped function. This study can provide new insights to CH4 and CO2 sorption hysteresis on coal and other organic geomaterials.

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