Measurement of the surface areas of powders by krypton gas adsorption method. Construction and operation of the apparatus

1966 ◽  
Author(s):  
S M Ahmed
Keyword(s):  
Gas Adsorption ◽  
Adsorption Method ◽  
Surface Areas ◽  
Method Construction

scholarly journals Study on Chlorinated Gas Adsorption Using Activated Carbon via Polyvinyl Chloride (PVC) Stepwise Pyrolysis Process

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1314
Author(s):  
Patiparn Boonruam ◽  
Piyachat Wattanachai ◽  
Settakorn Upasen
Keyword(s):  
Activated Carbon ◽  
Polyvinyl Chloride ◽  
Adsorption Process ◽  
Gas Adsorption ◽  
Chloride Ion ◽  
Pyrolysis Process ◽  
Acid Base ◽  
Surface Areas ◽  
Acid Base Titration ◽  
Specific Surface Areas

In this research, we studied the chlorinated gas adsorption process using activated carbon. Two types of granular activated carbon were employed: GAC800 and GAC1200; with specific surface areas of 800 m2/g and 1200 m2/g, respectively. In order to optimize the polyvinyl chloride (PVC) dehydrochlorination conditions, three parameters were studied: (i) the type of precursor—PVC and PVC mixed with charcoal (1:1 by weight)—(ii) the temperature—300 and 400 °C—and (iii) the retention time—30, 120, and 240 min. Mohr’s method and acid-base titration were used to estimate the captured amount of chlorinated gas. The results indicated that the PVC dehydrochlorination occurred completely about 69–73 wt.% at 400 °C for 240 min. The amount of chloride ion was detected around 1–2 mmol/LNaOH. The estimated HCl adsorption capacity for the GAC800 and GAC1200 samples potentially absorbed 0.27 mgHCl/gGAC and 0.21 mgHCl/gGAC, respectively. In addition, the efficiency for GAC800 and GAC1200 was reported to 37.95% and 28.92%, respectively.

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 Determination of porous structure parameters of coal particles to describe thermal conversion processes

2019 ◽  
Vol 109 ◽  
pp. 00101
Author(s):  
Oleksandr Topal ◽  
Iryna Holenko ◽  
Inna Diakun
Keyword(s):  
Porous Structure ◽  
Gas Adsorption ◽  
Thermal Conversion ◽  
Structure Parameters ◽  
Adsorption Method ◽  
Coal Particles ◽  
Different Temperatures ◽  
Char Reactivity ◽  
Determination Of Parameters

The results of determination of parameters of porous structure of coal and char particles are presented. They were determined using gas adsorption method and thermal decomposition of particles in air oxygen. The porous structure parameters allow predicting char reactivity change at different temperatures as well as during conversion in accordance with Random Pore Model (RPM-model).

Surface area and microstructure of microwave activated crumb rubber modifier and its influence on high temperature properties of crumb rubber modifier binders

2020 ◽  
Vol 10 (2) ◽  
pp. 272-277 ◽  
Author(s):  
Bo Li ◽  
Xuwei Zhu ◽  
Xingjun Zhang ◽  
Xiaolong Yang ◽  
Xiuli Su
Keyword(s):  
High Temperature ◽  
Surface Area ◽  
Gas Adsorption ◽  
Treatment Time ◽  
Particle Surface ◽  
Microwave Treatment ◽  
Crumb Rubber ◽  
Adsorption Method ◽  
Temperature Performance ◽  
Mechanism Of Interaction

Crumb rubber pretreatment by microwave before blending with an asphalt matrix can address and improve the modification problem of of crumb rubber modifier (CRM) asphalt plant. In this research, the surface area and microstructure of microwave activated CRM and high-temperature performance of CRM asphalt were investigated to characterize the mechanism of interaction between activated CRM blends added and base asphalt. The surface area and microstructure of CRM were measured by gas adsorption method and the scanning electron microscopy (SEM) respectively when CRM was activated using microwave treatment time (30 s, 60 s, 90 s, 120 s and 150 s). The complex shear modulus (G*) and the phase angle (δ) of the CRM asphalt were measured by Dynamic Shear Rheometer (DSR) test. The results indicated that microwave treatment produced more porous structure and agglomeration phenomenon than control one for a given activated time of CRM. The flocculent structure was the most obvious one and agglomeration phenomenon was the most significant one for the particle surface microwave activated 90 s. The δ decreased and G* increased as CRM blends activated time increased before a certain time using the same frequency of microwave treatment. The G*/sinδ of CRM blends was the maximum when CRM activated for 90 s using microwave treatment. Both surface area and microstructure of the CRM influenced the high-temperature performance of CRM binders.

scholarly journals Experimental Investigation of the Adsorption Characteristics of Mixed Coal and Variations of Specific Surface Areas before and after CH4 Adsorption

2019 ◽  
Vol 9 (3) ◽  
pp. 524 ◽  
Author(s):  
Pengxiang Zhao ◽  
Hui Liu ◽  
Shugang Li ◽  
Haifei Lin ◽  
Yongyong Jia ◽  
...  
Keyword(s):  
Specific Surface ◽  
Laboratory Tests ◽  
Gas Adsorption ◽  
Longwall Face ◽  
Adsorption Volume ◽  
Adsorption Characteristics ◽  
Surface Areas ◽  
Before And After ◽  
Tectonic Coal ◽  
Specific Surface Areas

Tectonic coal is a kind of soft coal that is generated during tectonic movement. Gas outbursts usually occur in seams containing both virgin coal and tectonic coal. To reveal the adsorption characteristics of this type of coal seam (containing both virgin coal and tectonic coal), both tectonic coal and virgin coal were collected from the same longwall face and a series of laboratory tests were conducted, including coal sorption tests and pore specific surface measurements. Both the tectonic coal and virgin coal were crushed into coal powder (0.18–0.25 mm) for the coal sorption tests. In these laboratory tests, different mass ratios between tectonic coal and virgin coal were tested. We found that with the increase of the percentage of tectonic coal, the adsorption volume showed a rising trend, reached its maximum value, and then decreased. The specific surface areas of the mixed coal samples had the same evolution trends as those of the adsorption volume. From the laboratory tests, we found that when the mass ratio of virgin coal to tectonic coal was 1:1, both the adsorption volume and the specific surface areas reached their maximum values. Due to the percentage variation of the tectonic coal in the panel with the advancement of the longwall face, when the tectonic coal accounted for 50% of the total coal, the gas content would rise. Thus, proper measures should be adopted for outburst hazards control. The mathematical model between the change of specific surface area and the stress and strain of pore expansion before and after gas adsorption was established, and the relationship between the change of pore structure and gas emission before and after gas adsorption was obtained. It provides a theoretical basis for further research on coal and gas outburst mechanisms.

scholarly journals Studies on sealing of anodic oxide coatings of aluminum by gas adsorption method

1972 ◽  
Vol 22 (3) ◽  
pp. 193-198
Author(s):  
Kizo SHIBATA ◽  
Hiromitsu KAMON ◽  
Shoichi ANADA ◽  
Kiyoshi TAKESHITA
Keyword(s):  
Gas Adsorption ◽  
Anodic Oxide ◽  
Oxide Coatings ◽  
Adsorption Method

Estimating the NMR surface relaxivity of Eocene sandstones: a comparison of different approaches

Geophysics ◽  
2020 ◽  
pp. 1-44
Author(s):  
Zeyu Zhang ◽  
Andreas Weller
Keyword(s):  
Relaxation Time ◽  
Pore Radius ◽  
Gas Adsorption ◽  
Fractal Theory ◽  
Relaxation Times ◽  
Adsorption Method ◽  
Throat Radius ◽  
Reliable Determination ◽  
Surface Relaxivity ◽  
Nmr Relaxometry

Nuclear magnetic resonance (NMR) relaxometry typically involves the analysis of a relaxation time distribution. The surface relaxivity ( ρ) is the key parameter that relates the relaxation time to the pore radius. Only a good estimate of the surface relaxivity enables a reliable determination of the pore radius distribution in a rock or sediment sample. A wide variety of approaches for the estimation of ρ has been proposed; however, the accuracy of ρ determination approaches has rarely been checked. We have compared different approaches of ρ determination for a set of Eocene sandstone samples. Most approaches based on a weighted logarithmic mean of relaxation times or the peak relaxation time result in significant underestimation of ρ. However, the correct weighting of the set of relaxation times proved to be a crucial approach in ρ determination. The consequent application of geometric rules suggests the application of the weighted harmonic mean ( Thm). The specific surface area per unit pore volume ( Spor), which results from the gas adsorption method, is another crucial parameter in most approaches for ρ estimation. The quantities Thm and Spor depend on the resolution of the used method. Applying the fractal theory, we adopt an approach that performs an upscaling of Spor to the resolution of the NMR relaxometry. Using equal resolution for Thm and Spor, we obtain more reliable ρ estimates. The resulting ρ values are comparable with the ones determined by using the median relaxation time from NMR and the median pore-throat radius from the mercury injection capillary pressure method.

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