Investigation of the methane adsorption characteristics of marine organic-rich shale: A case study of the lower Cambrian Niutitang Shale in the Fenggang block, northern Guizhou Province, South China

2018 ◽  
Vol 6 (4) ◽  
pp. T819-T833 ◽  
Author(s):  
Yang Gu ◽  
Wenlong Ding ◽  
Min Yin ◽  
Ruyue Wang ◽  
Baocheng Jiao ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Adsorption Capacity ◽  
Surface Area ◽  
South China ◽  
Pore Volume ◽  
Lower Cambrian ◽  
Methane Adsorption ◽  
Guizhou Province ◽  
Average Value

The marine shale in South China has great gas exploration potential, and exploration in the Sichuan Basin has been successful, but the degree of exploration remains low in the Guizhou Province. We used organic geochemical analyses (total organic carbon content and kerogen type), scanning electron microscopy (SEM), field emission SEM, nuclear magnetic resonance (NMR), X-ray diffraction analysis, and low-temperature [Formula: see text] and [Formula: see text] adsorption experimental methods to study the micropore types and pore structures and their effects on the methane adsorption capacity of organic-rich shales found in the Fenggang block in northern Guizhou Province. The results indicate that the microscopic surface porosity of the lower Cambrian Niutitang Formation ranges from 2.88% to 5.34%, with an average value of 3.86%. Based on nitrogen adsorption methods, the range of the average pore size distribution is 4.6–9.491 nm, with an average value of 6.68 nm. All of the samples exhibit significant unimodal distributions. The main pore size is less than 10 nm, and these pores account for most of the mesopore volume, which is generally consistent with the NMR results. The methane adsorption capacity of the shale samples gradually increases in the range of 0–8 MPa at 30°C and reaches a maximum at approximately 10 MPa. Positive correlations were found between the gas content and specific surface area, total pore volume, and micropore volume. These strong correlations indicate that the Niutitang Shale has a high specific surface area, a high pore volume, and narrow-diameter pores, demonstrating that it has a high gas adsorption capacity. The results of this study provide valuable information regarding the adsorption characteristics of marine shales and the factors that affect those characteristics.

The relationship between geotechnical index properties and the pore-size distribution of compacted clayey silts

2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Nazile Ural
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Correlation Coefficients ◽  
Liquid Limit ◽  
Index Properties

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

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

2011 ◽  
Vol 239-242 ◽  
pp. 2274-2279 ◽  
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).

scholarly journals Effects of the Pyrolysis Temperature on Adsorption of Carbamazepine and Ibuprofen by NaOH Pre-treated Pine Sawdust Biochars

2020 ◽  
Vol 42 (2) ◽  
pp. 29-39
Author(s):  
Jinwoo Kwak ◽  
Sangwoo Park ◽  
Jaegwan Shin ◽  
Kangmin Chon
Keyword(s):  
Ionic Strength ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pyrolysis Temperature ◽  
Repulsive Interaction ◽  
Pine Sawdust ◽  
Adsorption Mechanisms

Objective: The main purpose of this study was to examine the impacts of the pyrolysis temperature on the removal of pharmaceuticals (i.e., ibuprofen (IBF) and carbamazepine (CBZ)) using NaOH pre-treated biochars produced from pine sawdusts.Methods:Two different types of kinetic and isotherm models were applied to investigate the adsorption mechanisms of IBF and CBZ by the NaOH pre-treated biochars produced at 600℃ (PB-600) and 800℃ (PB-800). In addition, the removal efficiencies of IBF and CBZ by PB-600 and PB-800 were compared under various conditions (adsorbent doses: 5-40 mg/L; 20-160 mg/L; temperature: 15-45℃; ionic strength: 0-0.5 M) to assess their feasibility as an alternative adsorbent for the removal of pharmaceuticals. Results and Discussion:PB-800 could more effectively remove CBZ and IBF than PB-600 because of its larger specific surface area (PB-600 = 408.70 m<sup>2</sup>/g; PB-800 = 472.92 m<sup>2</sup>/g), pore volume (PB-600 = 0.336 cm<sup>3</sup>/g; PB-800 = 0.658 cm<sup>3</sup>/g), and pore size (PB-600 = 4.63 nm; PB-800 = 6.25 nm). The Langmuir isotherm was more suitable for adsorption of IBF by PB-600 and the Freundlich isotherm was well fitted to the adsorption of CBZ by PB-600 and adsorption of CBZ and IBF by PB-800. The adsorption of CBZ by PB-600 and PB-800 was not affected by temperature while the removal efficiency of IBF was decreased with increasing the temperature due to the increased repulsive interaction between IBF and the biochars. Furthermore, the effects of the ionic strength on the adsorption of IBF were more pronounced than that of CBZ due to the differences in the surface charge properties.Conclusions:The higher pyrolysis temperature can improve the physicochemical properties of the NaOH pre-treated pine sawdust biochars associated with the removal of the pharmaceuticals (i.e., CBZ and IBF). Moreover, the adsorption mechanisms of CBZ and IBF by the biochars were strongly influenced by their specific surface area, pore volume and pore size.

scholarly journals The influence factors for gas adsorption with different ranks of coals

2017 ◽  
Vol 36 (3-4) ◽  
pp. 904-918 ◽  
Author(s):  
Deyong Guo ◽  
Xiaojie Guo
Keyword(s):  
Moisture Content ◽  
Specific Surface ◽  
Pore Structure ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Total Pore Volume ◽  
Factors Influencing

In this paper, scanning electron microscopy, low-temperature N2 adsorption and CH4 isothermal adsorption experiments were performed on 11 coal samples with Ro,max between 0.98 and 3.07%. The pore structure characteristics of coals (specific surface area, total volume distribution) were studied to assess the gas adsorption capacity. The results indicate that there is significant heterogeneity on coal surface, containing numerous channel-like pores, bottle-shaped pores and wedge-shaped pores. Both Langmuir volume (VL) and Langmuir pressure (PL) show a stage change trend with the increase of coalification degree. For different coalification stages, there exist different factors influencing the VL and PL values. For low-rank coals (Ro,max < 1.1%), the increase of VL values and decrease of PL values are mainly due to the abundant primary pore and fracture within coal. For middle-rank coals (1.1% < Ro,max < 2.1%), the moisture content, vitrinite content and total pore volume are all the factors influencing VL, and the reduction of PL is mainly attributed to the decrease of moisture content and inertinite content. Meanwhile, this result is also closely related to the pore shape. For high-rank coals (Ro,max > 2.1%), VL values gradually increase and reach the maximum. When the coal has evolved into anthracite, liquid hydrocarbon within pore begins pyrolysis and gradually disappears, and a large number of macropores are converted into micropores, leading to the increase of specific surface area and total pore volume, corresponding to the increase of VL. In addition, the increase of vitrinite content within coal also contributes to the increase of VL. PL, reaches the minimum, indicating that the adsorption rate reaches the largest at the low pressure stage. The result is mainly controlled by the specific surface area and total pore volume of coal samples. This research results will provide a clearer insight into the relationship between adsorption parameters and coal rank, moisture content, maceral composition and pore structure, and it is of great significance for better assessing the gas adsorption capacity.

Hierarchical TiO2 spherical nanostructures with tunable pore size, pore volume, and specific surface area: facile preparation and high-photocatalytic performance

2012 ◽  
Vol 2 (9) ◽  
pp. 1933 ◽  
Author(s):  
Baoshun Liu ◽  
Kazuya Nakata ◽  
Munetoshi Sakai ◽  
Hidenori Saito ◽  
Tsuyoshi Ochiai ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Photocatalytic Performance ◽  
Facile Preparation

Improved Photocatalytic Activity of La3+-Doped Bi2O3

2011 ◽  
Vol 239-242 ◽  
pp. 86-89 ◽  
Author(s):  
Jun Zeng ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Shao Hua Wang ◽  
Wei Hu
Keyword(s):  
Photocatalytic Activity ◽  
Binding Energy ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Diffuse Reflectance ◽  
Bet Surface Area

In this paper, Bi2O3 doped with different amount of La3+ was prepared. The prepared photocatalysts were characterized by BET, XRD, UV-VIS diffuse reflectance and XPS. The results show that 3%La3+-Bi2O3 prepared has the highest BET surface area, pore volume, the smallest pore size. 3%La3+-Bi2O3 exhibits the best photocatalytic activity. The results of further experiments show that the specific surface area, UV-Vis diffuse reflectance and the binding energy all play an important role in promotion of photocatalytic activity of Bi2O3 nanostructure.

New Insight Technique for Synthesis of Silica Gel from Rice Husk Ash by Using Microwave Radiation

2014 ◽  
Vol 1025-1026 ◽  
pp. 574-579 ◽  
Author(s):  
Nuchanaporn Pijarn ◽  
Pichit Galajak
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Silica Gel ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Pore Volume ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Microwave Technique

Silica gel is the chemical substance that has many good advantages such as absorbed moisture, porosity, small diameter, high surface area, and lightweight. It was synthesized by using rice husk ash via sol – gel heating in the microwave technique. The objectives in this work compose of synthesis silica gel by using the microwave technique before characterizatization. This raw material was archived from rice husk ash, obtained from agricultural waste. The silica gel, synthesized by conventional method (CVM) and commercial silica gel (COM), was also studied for comparison purposes. The results showed that successfully synthesized the silica gel by sol - gel technique using microwave. The XRD pattern of silica gel enhanced from this method was not sinificantly different as compared with CVM and COM methods. And the physical properties of this technique could be debated. The particle size of silca gel was determined by zetasizer and it was approxmately 50-70 nm. The pore size diameter, pore volume, and specific surface area of silica gel were calculated by Flowsorb II and a Quantachrome Autosorp-1. The pore size diameter, pore volume, and specific surface area of silica gel are 10-30 nm, 0.7-1.0 cm3/g, and 400-700 m2/g, respectively. Consequently, this work is considered to be the waste to make useful, and a great way to save energy and time in the silica gel synthesis.

scholarly journals Influence of compressing pressure on macro void formation of carbon monolith for methane adsorption

2018 ◽  
Vol 18 (44) ◽  
pp. 24-35
Author(s):  
Narandalai B ◽  
W G Shim ◽  
M S Balathanigaimani ◽  
H Moon
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Packing Density ◽  
Activated Carbons ◽  
Void Formation ◽  
Methyl Cellulose ◽  
Methane Adsorption ◽  
Carbon Monolith

Carbon monoliths for adsorbed natural gas (ANG) storage were prepared from Mongolian anthracite-based activated carbons using carboxy-methyl cellulose as a binder under different compressing pressures. Nitrogen adsorption/desorption experiments were carried out to obtain the specific surface area, pore volume, and pore size distribution of the monoliths.  Methane adsorption experiments on the carbon monoliths were conducted at different temperatures and pressures up to around 3.5 MPa in a high pressure volumetric adsorption apparatus. As expected, adsorption results indicated that the methane adsorption capacity of the carbon monoliths increased with increasing specific surface area and packing density.  The maximum volumetric adsorption of methane was observed as 163 V/V at 293 K and 3.5 MPa on a carbon monolith sample, PMAC1/2-3-65, that does not have the highest specific surface area but relatively high packing density comparing with other monoliths, which implies that two physical properties contribute contradictorily to the methane adsorption capacity.  Based on experimental results, the carbon monoliths prepared from Mongolian anthracite-based activated carbons can be promising media for ANG storage application.

scholarly journals Univariate and Multivariate Analyses of Influencing Factors on Methane Adsorption Capacity of Semianthracite

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shihui Hou ◽  
Xiaoming Wang ◽  
Yudong Yuan ◽  
Sidong Pan ◽  
Zheng Dang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Influencing Factors ◽  
Specific Surface Area ◽  
Multivariate Analyses ◽  
Methane Adsorption ◽  
Coal Rank ◽  
Strong Positive Correlation ◽  
Quantification Theory

Methane adsorption isotherm experiments on semianthracite (2.00-2.33% R o , max ) collected from the Xin’an coal mine, Henan Province, China, were conducted to investigate the effects of pore structure, coal quality, coal maceral, and coal rank on methane adsorption capacity with applications of univariate and multivariate analyses. Methane adsorption capacity varies significantly from 12.03 to 28.40 cm3/g. In univariate analysis, methane adsorption capacity has a strong positive correlation with pore specific surface area, weak positive correlations with pore volume and ash content, and weak negative correlations with moisture content and inertinite content. No correlation is observed between methane adsorption capacity and coal rank. In multivariate analysis, the mathematical model of methane adsorption capacity affected by the combined individual variables is established based on quantification theory I. There are similarities and differences between the two analyses. The similarities are that pore specific surface area has the greatest contribution to methane adsorption capacity, while coal rank has the least contribution. The differences are reflected in two aspects. Firstly, the other influencing factors contribute differently to methane adsorption capacity. Secondly, the positive or negative correlations of some influencing factors present the opposite. The mathematic model synthetically covers the combined effects of the influencing factors, which is more representative in evaluating methane adsorption capacity.

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