Biochar total surface area and total pore volume determined by N2 and CO2 physisorption are strongly influenced by degassing temperature

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.

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An Eco-Friendly Process for Removal of Lead from Aqueous Solution

Modern Applied Science ◽

10.5539/mas.v11n5p47 ◽

2017 ◽

Vol 11 (5) ◽

pp. 47 ◽

Cited By ~ 1

Author(s):

Heman A. Smail ◽

Kafia M. Shareef ◽

Zainab H. Ramli

Keyword(s):

Heavy Metal ◽

Oxalic Acid ◽

Surface Area ◽

Pore Volume ◽

Metal Ion ◽

Adsorption Equilibrium ◽

Total Pore Volume ◽

Heavy Metal Ion ◽

Bet Surface Area ◽

Barley Husk

The adsorption of lead (Pb II) ion on different types of synthesized zeolite was investigated. The BET surface area, total pore volume & average pore size distribution of these synthesized zeolites were determined by adsorption isotherms for N2, the surface area & total pore volume of their sources were found by adsorption isothermN2.The adsorption equilibrium was measured after 24h at room temperature (RT) & concentration 10mg.L-1 of Pb (II) was used. The adsorption of heavy metal Pb (II) on four different prepared zeolites (LTA from Montmorillonite clay, FAU(Y)-B.H (G2) from Barley husk, Mordenite (G1) from Chert rock, FAU(X)-S.C (G3) from shale clay & modified Shale clay by oxalic acid (N1) & sodium hydroxide (N2)), were compared with the adsorption of their sources by using static batch experimental method. The major factors affecting the heavy metal ion sorption on different synthesized zeolites & their sources were investigated. The adsorption equilibrium capacity (Qm) of Pb (II) ion for different synthesized zeolites ordered from (N1>N2>LTA>G3>G2>G1&for their sources ordered Shale clay >Montmorilonite> Barley husk>Chert rock. The atomic absorption spectrometry was used for analysis of lead heavy metal ion, the obtained results in this study showed that the different synthesized zeolites were efficient ion exchanges for removing heavy metal, in particular, the modified zeolite from shale clay by oxalic acid.

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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

Energy Exploration & Exploitation ◽

10.1177/0144598718790319 ◽

2018 ◽

Vol 37 (1) ◽

pp. 251-272 ◽

Cited By ~ 9

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.

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Activated Carbons from Thermoplastic Precursors and Their Energy Storage Applications

Nanomaterials ◽

10.3390/nano9060896 ◽

2019 ◽

Vol 9 (6) ◽

pp. 896 ◽

Cited By ~ 2

Author(s):

Hye-Min Lee ◽

Kwan-Woo Kim ◽

Young-Kwon Park ◽

Kay-Hyeok An ◽

Soo-Jin Park ◽

...

Keyword(s):

Electron Microscope ◽

Specific Surface ◽

Surface Area ◽

Field Emission ◽

Specific Surface Area ◽

Pore Volume ◽

Activated Carbons ◽

Total Pore Volume ◽

Cross Linking ◽

Mesopore Volume

In this study, low-density polyethylene (LDPE)-derived activated carbons (PE-AC) were prepared as electrode materials for an electric double-layer capacitor (EDLC) by techniques of cross-linking, carbonization, and subsequent activation under various conditions. The surface morphologies and structural characteristics of the PE-AC were observed by field-emission scanning electron microscope, Cs-corrected field-emission transmission electron microscope, and X-ray diffraction analysis, respectively. The nitrogen adsorption isotherm-desorption characteristics were confirmed by Brunauer–Emmett–Teller, nonlocal density functional theory, and Barrett–Joyner–Halenda equations at 77 K. The results showed that the specific surface area and total pore volume of the activated samples increased with increasing the activation time. The specific surface area, the total pore volume, and mesopore volume of the PE-AC were found to be increased finally to 1600 m2/g, 0.86 cm3/g, and 0.3 cm3/g, respectively. The PE-AC also exhibited a high mesopore volume ratio of 35%. This mesopore-rich characteristic of the activated carbon from the LDPE is considered to be originated from the cross-linking density and crystallinity of precursor polymer. The high specific surface area and mesopore volume of the PE-AC led to their excellent performance as EDLC electrodes, including a specific capacitance of 112 F/g.

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Surface and Catalytic Properties of γ-Irradiated Cr2O3/Al2O3 Solids

Adsorption Science & Technology ◽

10.1177/026361749701500607 ◽

1997 ◽

Vol 15 (6) ◽

pp. 465-476 ◽

Cited By ~ 8

Author(s):

G.A. El-Shobaky ◽

A.M. Ghozza ◽

G.M. Mohamed

Keyword(s):

Catalytic Activity ◽

Co Oxidation ◽

Surface Area ◽

Pore Volume ◽

Active Sites ◽

Catalytic Properties ◽

Total Pore Volume ◽

Bet Surface Area ◽

Two Samples ◽

Γ Rays

Two samples of Cr2O3/Al2O3 were prepared by mixing a known mass of finely powdered Al(OH)3 with a calculated amount of CrO3 solid followed by drying at 120°C and calcination at 400°C. The amounts of chromium oxide employed were 5.66 and 20 mol% Cr2O3, respectively. The calcined solid specimens were then treated with different doses of γ-rays (20–160 Mrad). The surface and catalytic properties of the different irradiated solids were investigated using nitrogen adsorption at −196°C and the catalysis of CO oxidation by O2 at 300–400°C. The results revealed that γ-rays brought about a slight decrease in the BET surface area, SBET (15%), and in the total pore volume, Vp (20%), of the adsorbent containing 5.66 mol% Cr2O3. The same treatment increased the total pore volume, Vp (36%), and the mean pore radius, r̄ (43%), of the other adsorbent sample without changing its BET surface area. The catalytic activities of both catalyst samples were found to increase as a function of dose, reaching a maximum value at 80–160 Mrad and 40 Mrad for the solids containing 5.66 and 20 mol% Cr2O3, respectively. The maximum increase in the catalytic activity measured at 300°C was 59% and 100% for the first and second catalyst samples, respectively. The induced effect of γ-irradiation on the catalytic activity was an increase in the concentration of catalytically active sites taking part in chemisorption and in the catalysis of CO oxidation by O2 without changing their energetic nature. This was achieved by a progressive removal of surface hydroxy groups during the irradiation process.

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Wheat straw carbon matrix wrapped sulfur composites as a superior cathode for Li–S batteries

RSC Advances ◽

10.1039/c5ra21416e ◽

2015 ◽

Vol 5 (121) ◽

pp. 100089-100096 ◽

Cited By ~ 25

Author(s):

Youmin Cheng ◽

Shaomin Ji ◽

Xijun Xu ◽

Jun Liu

Keyword(s):

Wheat Straw ◽

Surface Area ◽

Porous Carbon ◽

Pore Volume ◽

Rate Capability ◽

Total Pore Volume ◽

Carbon Matrix ◽

Cycling Performance

Wheat straw derived porous carbon with a surface area of 1066 m2g−1and total pore volume of 0.62 cm3g−1is used to synthesize WSC/S (74 wt%) cathode for Li–S batteries, which delivers a stable cycling performance and superior rate capability.

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The Influence of Sinterng Temperature on the Phase, Microstructure and Textual Properties of Hollow Hydroxyapatite Microspheres

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2274 ◽

2011 ◽

Vol 239-242 ◽

pp. 2274-2279 ◽

Cited By ~ 1

Author(s):

Ying Chun Wang ◽

Wen Hai Huang ◽

Ai Hua Yao ◽

De Ping Wang

Keyword(s):

Specific Surface ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

Pore Volume ◽

Sintering Temperature ◽

Total Pore Volume ◽

Precipitation Method ◽

Simple Method ◽

Air Atmosphere

A simple method to prepare hollow hydroxyapatite (HAP) microspheres with mespores on the surfaces is performed using a precipitation method assisted with Li2O-CaO-B2O3(LCB) glass fabrication process. This research is concerned with the effect of sintering temperature on the microstructure evolution, phase purity, surface morphology, specific surface area, and porosity after sintering process. The microspheres were sintered in air atmosphere at temperatures ranging from 500 to 900 °C. The starting hollow HAP microspheres and the sintered specimens were characterized by scanning electron microscope, X-ray diffractometer, specific surface area analyzer, and Hg porosimetry, respectively. The as-prepared microspheres consisted of calcium deficient hydroxyapatite. The results showed that the as-prepared hollow HAP microspheres had the highest specific surface areas, and the biggest total pore volume. The pore size distribution of the as-prepared hollow HAP microspheres were mainly the mesopores in the range of 2～40 nm. The specific surface area and total pore volume of hollow HAP microspheres decreased with increasing sintering temperature. Whereas the mean pore size increased with increasing sintering temperature. It showed that at 700°C, Ca-dHAP decomposes into a biphasic mixture of HAP and β-calcium phosphate(TCP).

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Preparation of Activated Carbons from Lignite for Electrochemical Capacitors by Microwave and Electrical Furnace Heating

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.2472 ◽

2011 ◽

Vol 194-196 ◽

pp. 2472-2479 ◽

Cited By ~ 5

Author(s):

Bao Lin Xing ◽

Chuan Xiang Zhang ◽

Lun Jian Chen ◽

Guang Xu Huang

Keyword(s):

Specific Surface ◽

Specific Capacitance ◽

Surface Area ◽

Specific Surface Area ◽

Pore Volume ◽

Activated Carbons ◽

Electrochemical Capacitors ◽

Weight Ratio ◽

Total Pore Volume ◽

Electrochemical Performances

Activated carbons (ACs) were prepared from lignite by microwave (MW) and electrical furnace (EF) heating with KOH as activation agent. In order to compare pore structures and electrochemical performances of ACs prepared by both heating methods, the ACs were characterized by N2 adsorption at 77K, X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical performances of Electrochemical capacitors (ECs) with ACs as electrodes in 3mol/L KOH electrolyte were evaluated by constant current charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the pore structures of ACs prepared by MW and EF heating significantly enhance when the weight ratio of KOH to coal increases from 2 to 4. The BET specific surface area, total pore volume, the ratio of mesopore and average pore diameter of ACs prepared by MW heating (denoted as AC-MW4) reaches 2094m2/g, 1.193cm3/g, 53.6%, 2.28nm when the weight ratio of KOH to coal is 4, and ACs prepared by EF heating (denoted as AC-EF4) reaches 2580m2/g, 1.683cm3/g, 67.3%, 2.61nm. The ECs with AC-MW4 and AC-EF4 as electrodes present a high specific capacitance of 348F/g and 377F/g at a current density of 50mA/g, and still remain 325F/g and 350F/g after 500 cycles, respectively. Although the specific surface area, total pore volume and specific capacitance of ACs prepared by MW heating are slightly lower than EF heating, taking into account the heating time in the activation process, ACs prepared by EF heating needs approximate 140min, while MW heating only needs 10min, which have demonstrated that microwave heating technology is a promising and efficient technique to prepare ACs.

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Preparation and Characterization of Electrospun Carbon Nanofibers with Na2CO3/H3PO4 Activation

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.135.81 ◽

2008 ◽

Vol 135 ◽

pp. 81-84 ◽

Cited By ~ 2

Author(s):

Ji Sun Im ◽

Soo Jin Park ◽

Young Seak Lee

Keyword(s):

Phosphoric Acid ◽

Specific Surface ◽

Surface Area ◽

Carbon Nanofibers ◽

Pore Volume ◽

Total Pore Volume ◽

Chemical Agent ◽

Electrospinning Method ◽

Increase Surface Area

In this work, carbon nanofibers(CNFs) were prepared by using electrospinning method. Phosphoric acid and sodium carbonate activation of CNFs were conducted to increase surface area and pore volume. Pore structures of activated CNFs were developed with increasing surface area and pore volume through activation. Specific surface area increased about 60 times and total pore volume developed around 120 times. Activated CNFs have different pore distribution with different chemical agent.

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Carbonization Temperature Effect over Activated Carbon Porosity Derived from Industrial Processing Waste

Academic Perspective Procedia ◽

10.33793/acperpro.02.03.133 ◽

2019 ◽

Vol 2 (3) ◽

pp. 1205-1209

Author(s):

Hasan Sayğılı

Keyword(s):

Activated Carbon ◽

Surface Area ◽

Pore Volume ◽

Activated Carbons ◽

Waste Product ◽

Total Pore Volume ◽

Carbonization Temperature ◽

Bet Surface Area ◽

Processing Waste ◽

Industrial Processing

The influence of carbonization temperature (CT) on pore properties of the prepared activated carbon using lentil processing waste product (LWP) impregnated with potassium carbonate was studied. Activated carbons (ACs) were obtained by impregnation with 3:1 ratio (w/w) K2CO3/LWP under different carbonization temperatures at 600, 700, 800 and 900 oC for 1h. Activation at low temperature represented that micropores were developed first and then mesoporosity developed, enhanced up to 800 oC and then started to decrease due to possible shrinking of pores. The optimum temperature for LWP was found to be around 800 oC on the basis of total pore volume and the Brunauer-Emmett-Teller (BET) surface area. The optimum LWPAC sample was found with a CT of 800 oC, which gives the highest BET surface area and pore volume of 1875 m2/g and 0.995 cm3/g, respectively.

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