scholarly journals Evolutions of CO2 Adsorption and Nanopore Development Characteristics during Coal Structure Deformation

2020 ◽  
Vol 10 (14) ◽  
pp. 4997
Author(s):  
Linlin Wang ◽  
Zhengjiang Long
Keyword(s):  
Co2 Adsorption ◽  
Nitrogen Adsorption ◽  
Adsorption Method ◽  
Deformation Degree ◽  
Coal Structure ◽  
Structure Deformation ◽  
Coal Deformation ◽  
Key Factor ◽  
Tectonically Deformed Coals ◽  
Nanopore Structure

The coal structure deformation attributed to actions of tectonic stresses can change characteristics of nanopore structure of coals, affecting their CO2 adsorption. Three tectonically deformed coals and one undeformed coal were chosen as the research objects. The isotherm adsorption experiments of four coal specimens were carried out at the temperature of 35 °C and the pressure of 0 to 7 MPa. Nanopore structures were characterized using the liquid nitrogen adsorption method. The results show that there exist maximum values of excess and absolute adsorption capacity, which increase with increasing coal deformation degree. As the degree of coal deformation increases, the pore volume and specific surface area present an obvious increasing trend in the case of micropores, exhibiting an increase at first (cataclastic coal and ganulitic coal) and then stabilization (crumple coal), in the case of mesopores, and showing a gradual decrease in the case of macropores. The mesopores are the key factor of CO2 adsorption of tectonically deformed coals, followed by the micropores and the limited effect of macropores at the strong coal deformation stage.

Extraordinary Stability of Structural and Electronic Properties of Tin Oxide Nanoparticles Formed by Soft Chemistry

2010 ◽  
Vol 75 ◽  
pp. 36-42 ◽  
Author(s):  
Marina Rumyantseva ◽  
Irina Zhurbina ◽  
Elena Varechkina ◽  
Siranuysh Badalyan ◽  
Alexander Gaskov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Tin Dioxide ◽  
Hydrogen Reduction ◽  
Nitrogen Adsorption ◽  
Ammonia Solution ◽  
Adsorption Method ◽  
X Ray ◽  
Wet Chemical Synthesis ◽  
Tin Chloride

Powders of tin dioxide (SnO2) have been prepared by two different modifications of wet chemical synthesis, i.e. (i) by conventional hydrolysis of tin chloride dissolved in aqueous ammonia solution and (ii) by precipitation from tin chloride dissolved in aqueous hydrazine monohydrate (N2H4*H2O) solution. The prepared gels were dried and then annealed at different temperatures varied from 300 to 700 oC in order to form nanocrystals. Structure and optical properties of the samples were investigated by using X-ray diffraction, transmission electron microscopy, thermoprogrammable hydrogen reduction, low temperature nitrogen adsorption method, photoluminescence, infra-red absorption, Raman spectroscopy, and X-ray photoelectron spectroscopy. The samples prepared by hydrazine-based method are characterized by surface area about 127-188 m2/g with high sintering resistance. The optical spectroscopy data revealed pure crystallinity and high defect concentration for the samples prepared by hydrazine-based method. The experimental results are discussed in view of different states of chemisorbed oxygen on SnO2 nanocrystal surfaces, which determine electronic and optical properties of the prepared samples.

scholarly journals Fractal Characterization of Nanopore Structure in Shale, Tight Sandstone and Mudstone from the Ordos Basin of China Using Nitrogen Adsorption

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 583 ◽  
Author(s):  
Xiaohong Li ◽  
Zhiyong Gao ◽  
Siyi Fang ◽  
Chao Ren ◽  
Kun Yang ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pressure Range ◽  
Ordos Basin ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Relative Pressure ◽  
Tight Sandstone ◽  
Porosity And Permeability ◽  
The Ordos Basin ◽  
Nanopore Structure

The characteristics of the nanopore structure in shale, tight sandstone and mudstone from the Ordos Basin of China were investigated by X-ray diffraction (XRD) analysis, porosity and permeability tests and low-pressure nitrogen adsorption experiments. Fractal dimensions D1 and D2 were determined from the low relative pressure range (0 < P/P0 < 0.4) and the high relative pressure range (0.4 < P/P0 < 1) of nitrogen adsorption data, respectively, using the Frenkel–Halsey–Hill (FHH) model. Relationships between pore structure parameters, mineral compositions and fractal dimensions were investigated. According to the International Union of Pure and Applied Chemistry (IUPAC) isotherm classification standard, the morphologies of the nitrogen adsorption curves of these 14 samples belong to the H2 and H3 types. Relationships among average pore diameter, Brunner-Emmet-Teller (BET) specific surface area, pore volume, porosity and permeability have been discussed. The heterogeneities of shale nanopore structures were verified, and nanopore size mainly concentrates under 30 nm. The average fractal dimension D1 of all the samples is 2.1187, varying from 1.1755 to 2.6122, and the average fractal dimension D2 is 2.4645, with the range from 2.2144 to 2.7362. Compared with D1, D2 has stronger relationships with pore structure parameters, and can be used for analyzing pore structure characteristics.

scholarly journals A Study of the Micropore Structure of Carbonized Rayon Yarn by Nitrogen Adsorption and Nonane Pre-Adsorption

1985 ◽  
Vol 2 (2) ◽  
pp. 89-95 ◽  
Author(s):  
J. N. Bohra ◽  
K. S. W. Sing
Keyword(s):  
External Surface ◽  
Nitrogen Adsorption ◽  
The Other ◽  
Adsorption Method ◽  
Micropore Structure ◽  
Surface Areas ◽  
Three Samples ◽  
Two Samples ◽  
Before And After ◽  
Gain Access

Adsorption isotherms of nitrogen have been determined at 77 K on three samples of carbonized rayon yarn, both before and after the pre-adsorption of n-nonane. In their original state the three samples were all highly microporous. Application of the αs-method of isotherm analysis reveals that their micropore volumes were 0·17–0·19 cm3g−1 and their external surface areas 20–27 m2g−1 (the corresponding BET areas being 427–483 m2g−1). Nonane pre-adsorption resulted in blockage of the entire micropore structure only in the case of one sample: micropore volumes ∼0·1 cm3g−1 were still available for nitrogen adsorption in the other two samples. It appears that nitrogen molecules were able to gain access to some parts of these micropore structures through wider pore entrances which were not completely blocked by the pre-adsorbed nonane. The work has shown that the nonane pre-adsorption method requires further investigation before it can be used with confidence for the assessment of microporosity.

scholarly journals Activated carbons prepared from hazelnut shells, walnut shells and peanut shells for high CO2 adsorption

2017 ◽  
Vol 19 (2) ◽  
pp. 38-43 ◽  
Author(s):  
Katarzyna Lewicka
Keyword(s):  
Surface Area ◽  
Co2 Adsorption ◽  
Activated Carbons ◽  
Dft Method ◽  
Adsorption Method ◽  
Walnut Shells ◽  
Peanut Shells ◽  
Activating Agent ◽  
Hazelnut Shells ◽  
Bet Equation

Abstract Research treats about producing activated carbons for CO2 capture from hazelnut shells (HN), walnut shells (WN) and peanut shells (PN). Saturated solution of KOH was used as an activating agent in ratio 1:1. Samples were carbonized in the furnace in the range of temperatures 600°C–900°C. Properties of carbons were tested by N2 adsorption method, using BET equation, DFT method and volumetric CO2 adsorption method. With the increase of carbonization temperature specific surface area of studied samples increased. The largest surface area was calculated for samples carbonized at 900°C and the highest values of CO2 adsorption had samples: PN900 at 0°C (5.5 mmol/g) and WN900 at 25°C (4.34 mmol/g). All of the samples had a well-developed microporous structure.

scholarly journals Characterization and Modelling Studies of Activated Carbon Produced from Rubber-Seed Shell Using KOH for CO2 Adsorption

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 855 ◽  
Author(s):  
Azry Borhan ◽  
Suzana Yusup ◽  
Jun Wei Lim ◽  
Pau Loke Show
Keyword(s):  
Experimental Data ◽  
Activated Carbon ◽  
Co2 Adsorption ◽  
Chemical Activation ◽  
Freundlich Isotherm ◽  
Nitrogen Adsorption ◽  
Rubber Seed ◽  
Modelling Studies ◽  
Carbon Dioxide Co2 ◽  
Activation Conditions

Global warming due to the emission of carbon dioxide (CO2) has become a serious problem in recent times. Although diverse methods have been offered, adsorption using activated carbon (AC) from agriculture waste is regarded to be the most applicable one due to numerous advantages. In this paper, the preparation of AC from rubber-seed shell (RSS), an agriculture residue through chemical activation using potassium hydroxide (KOH), was investigated. The prepared AC was characterized by nitrogen adsorption–desorption isotherms measured in Micrometrices ASAP 2020 and FESEM. The optimal activation conditions were found at an impregnation ratio of 1:2 and carbonized at a temperature of 700 °C for 120 min. Sample A6 is found to yield the largest surface area of 1129.68 m2/g with a mesoporous pore diameter of 3.46 nm, respectively. Using the static volumetric technique evaluated at 25 °C and 1.25 bar, the maximum CO2 adsorption capacity is 43.509 cm3/g. The experimental data were analyzed using several isotherm and kinetic models. Owing to the closeness of regression coefficient (R2) to unity, the Freundlich isotherm and pseudo-second kinetic model provide the best fit to the experimental data suggesting that the RSS AC prepared is an attractive source for CO2 adsorption applications.

MICROWAVE ASSISTED K2CO3 PALM SHELL ACTIVATED CARBON AS SORBENT FOR CO2 ADSORPTION APPLICATION

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Usman Dadum Hamza ◽  
Noor Shawal Nasri ◽  
Nor Aishah Saidina Amin ◽  
Jibril Mohammed ◽  
Husna Mohd Zain
Keyword(s):  
Activated Carbon ◽  
Porous Carbon ◽  
Co2 Adsorption ◽  
Co2 Uptake ◽  
Adsorption Method ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Co2 Adsorption Capacity ◽  
Adsorption Equilibrium Data ◽  
Best Fit

Carbon dioxide is believed to be a major greenhouse gas (GHG) that contributes to global warming. In this study, palm shells were used as a precursor to prepare CO2 activated carbon sorbents via carbonization, chemical impregnation with K2CO3 and microwave activation.  Adsorption equilibrium data for CO2 adsorption on the porous carbon were obtained at different temperatures using static volumetric adsorption method. Langmuir, Freundlich, Sips and Toths models were used to correlate the experimental data. The CO2 adsorption capacity at 303.15, 343.15, 378.15 443.15 K and 1 bar on the sorbent was 2.71, 1.5, 0.77, 0.69 mmol/g respectively. Sips isotherm was found to have the best fit. The results indicated that the porous carbon sorbent prepared by carbonization and microwave K2CO3 assisted activation have good CO2 uptake. The porous carbons produced are therefore good candidates for CO2 adsorption applications

Study on Treating Isophthalonitrile Wastewater Using Immobilized Efficiently Coupling Microorganism

2011 ◽  
Vol 356-360 ◽  
pp. 581-584
Author(s):  
Li Zhang ◽  
Xiao Jie Wan ◽  
Wei Qing Han ◽  
Lian Jun Wang
Keyword(s):  
Sodium Alginate ◽  
Degradation Rate ◽  
Biological Aerated Filter ◽  
Ceramic Filler ◽  
Adsorption Method ◽  
Biological Technology ◽  
Key Factor ◽  
Scale Experiment ◽  
Cyano Groups ◽  
Aerated Filter

Isophthalonitrile(IPN) used in this study contains two cyano groups(-CN) attached to the m-benzene ring. The IPN wastewater is degraded by biological method of high efficiently coupling microorganism. The choice of carrier is the key factor of immobilized biological technology. Two immobilization methods, adsorption with ceramic as the carrier，embedding with Sodium Alginate(SA) and Polyvinyl Alcohol –Sodium Alginate(PVA-SA) as the carrier, the research is conducted into the degradation effects. Results showed that IPN biodegradation by adsorption method had the best effect degrading. The IPN degradation rate kept stable and was over 96%. Additionally, in order to demonstrate purification of the IPN wastewater. The laboratory-scale experiment was carried out in a biological aerated filter (BAF) that was filled with ceramic filler. Results also showed that the BAF reactor removed the IPN and the rate was over 95%.

scholarly journals Characterization of Coal Porosity for Naturally Tectonically Stressed Coals in Huaibei Coal Field, China

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
Xiaoshi Li ◽  
Yiwen Ju ◽  
Quanlin Hou ◽  
Zhuo Li ◽  
Mingming Wei ◽  
...  
Keyword(s):  
Surface Area ◽  
Pore Volume ◽  
Coalbed Methane ◽  
Nitrogen Adsorption ◽  
Ductile Deformation ◽  
Macromolecular Structure ◽  
Coal Field ◽  
Nanopore Structure ◽  
The Relationship

The enrichment of coalbed methane (CBM) and the outburst of gas in a coal mine are closely related to the nanopore structure of coal. The evolutionary characteristics of 12 coal nanopore structures under different natural deformational mechanisms (brittle and ductile deformation) are studied using a scanning electron microscope (SEM) and low-temperature nitrogen adsorption. The results indicate that there are mainly submicropores (2~5 nm) and supermicropores (<2 nm) in ductile deformed coal and mesopores (10~100 nm) and micropores (5~10 nm) in brittle deformed coal. The cumulative pore volume (V) and surface area (S) in brittle deformed coal are smaller than those in ductile deformed coal which indicates more adsorption space for gas. The coal with the smaller pores exhibits a large surface area, and coal with the larger pores exhibits a large volume for a given pore volume. We also found that the relationship betweenSandVturns from a positive correlation to a negative correlation whenS>4 m2/g, with pore sizes <5 nm in ductile deformed coal. The nanopore structure (<100 nm) and its distribution could be affected by macromolecular structure in two ways. Interconversion will occur among the different size nanopores especially in ductile deformed coal.

Surface Area of Nonporous Carbon Blacks and Area of the Adsorbed Nitrogen Molecule

1964 ◽  
Vol 37 (3) ◽  
pp. 630-634 ◽  
Author(s):  
Andries Voet
Keyword(s):  
Surface Area ◽  
Nitrogen Adsorption ◽  
Nitrogen Molecule ◽  
Adsorption Method ◽  
Chain Formation ◽  
Electron Micrography ◽  
Carbon Blacks ◽  
Surface Areas ◽  
Particle Chain ◽  
Lower Ratio

Abstract Surface areas of completely nonporous carbon blacks of widely varying particle chain formation (structure) have been determined by means of the nitrogen adsorption method as well as by electron micrography. Accurately determined densities in helium were used as the basis of calculations in the latter approach. It was found that the ratio of areas measured by nitrogen adsorption to electron micrographically determined surface areas is greatly dependent upon chain formation. A higher structural build-up leads to a lower ratio, explained by the observation that fusion areas in carbon chains are necessarily, though erroneously, counted as surfaces in electron micrography. The ratio differs markedly from unity, however, in low structure blacks, where fusion areas are negligible. By accepting the area of a nitrogen molecule adsorbed in a monolayer as being equal to that in the solid state, 13.8 A2, the ratio becomes unity for nonporous low structure blacks. It appears likely, therefore, that all surface area data based on the area of a nitrogen molecule in the liquid state of 16.2 A2 are too high by about 15 per cent of presently accepted values.

scholarly journals The Effect of Metal Materials on Heat Shock Protein 70B’ Gene Expression

2007 ◽  
Vol 1 (1) ◽  
pp. 14-17 ◽  
Author(s):  
Junko Okuda-Shimazaki ◽  
Akiko Yamamoto ◽  
Daisuke Kuroda ◽  
Takao Hanawa ◽  
Akiyoshi Taniguchi
Keyword(s):  
Gene Expression ◽  
Stainless Steel ◽  
Heat Shock ◽  
Austenitic Stainless Steel ◽  
Heat Shock Protein ◽  
Stainless Steels ◽  
Nitrogen Adsorption ◽  
Adsorption Method ◽  
Nickel Ions ◽  
Metal Materials

To avoid the toxic effect of released nickel ions and compounds from conventional stainless steels, nickel-free austenitic stainless steels have been developed. We previously established a new manufacturing process to produce nickel-free austenitic stainless steel that involves nitrogen adsorption treatment. Although the cytocompatibility of nickelfree austenitic stainless steel produced using this method has been evaluated using two viability assay, molecular level analysis, such as gene expression analysis, has not been previously performed. In the present study, the cytotoxicity of our nickel-free austenitic stainless steel, as well as of commercially available metal materials, was evaluated by analysis of heat shock protein 70B’ (HSP70B’) gene expression as a stress response marker. Furthermore, to investigate the effect of metal materials on cytotoxicity, HSP70B’ gene expression was quantified using human osteoblast-like SaOS-2 cells, human monocyte THP-1 cells and the mouse macrophage cell line J774A.1. We found no significant differences in HSP70B’ expression among the various metal materials, including the nickel-free austenitic stainless steel, indicating that the nickel-free austenitic stainless steel produced using our nitrogen adsorption method has the same cytocompatibility as commercially available metal materials.

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