Geological and Geophysical Criteria for Identifying Zones of High Gas Permeability of Coals (Using the Example of Kuzbass CBM Deposits)

2021 ◽  
pp. 217-229
A.G. Pogosyan
2014 ◽  
Vol 17 (8) ◽  
pp. 705-713 ◽  
Hikaru Maeda ◽  
Yoshihiro Hirata ◽  
Soichiro Sameshima ◽  
Taro Shimonosono

2020 ◽  
Adlai Katzenberg ◽  
Debdyuti Mukherjee ◽  
Peter J. Dudenas ◽  
Yoshiyuki Okamoto ◽  
Ahmet Kusoglu ◽  

<p>Limitations in fuel cell electrode performance have motivated the development of ion-conducting binders (ionomers) with high gas permeability. Such ionomers have been achieved by copolymerization of perfluorinated sulfonic acid (PFSA) monomers with bulky and asymmetric monomers, leading to a glassy ionomer matrix with chemical and mechanical properties that differ substantially from common PFSA ionomers (e.g., Nafion™). In this study, we use perfluorodioxolane-based ionomers to provide fundamental insights into the role of the matrix chemical structure on the dynamics of structural and transport processes in ion-conducting polymers. Through <i>in-situ</i> water uptake measurements, we demonstrate that ionomer water sorption kinetics depend strongly on the properties and mass fraction of the matrix. As the PFSA mass fraction was increased from 0.26 to 0.57, the Fickian swelling rate constant decreased from 0.8 s<sup>-1</sup> to 0.2 s<sup>-1</sup>, while the relaxation rate constant increased from 3.1×10<sup>-3</sup> s<sup>-1</sup> to 4.0×10<sup>-3</sup>. The true swelling rate, in nm s<sup>-1</sup>, was determined by the chemical nature of the matrix; all dioxolane-containing materials exhibited swelling rates ~1.5 - 2 nm s<sup>-1</sup> compared to ~3 nm s<sup>-1</sup> for Nafion. Likewise, Nafion underwent relaxation at twice the rate of the fastest-relaxing dioxolane ionomer. Reduced swelling and relaxation kinetics are due to limited matrix segmental mobility of the dioxolane-containing ionomers. We demonstrate that changes in conductivity are strongly tied to the polymer relaxation, revealing the decoupled roles of initial swelling and relaxation on hydration, nanostructure, and ion transport in perfluorinated ionomers. </p>

2019 ◽  
pp. 123-128
M. N. Nagornaya ◽  
A. V. Myshliavtsev ◽  
S. Ya. Khodakova

The subject of the study were samples of channel technical carbon K354, furnace technical carbon N121 and experimental – based on TUN121, oxidized with active forms of oxygen. Samples of carbon black were studied in the composition of a rubber mixture based on BK 1675N butyl rubber. The purpose of this study was to determine the possibility of using oxidized technical carbon N121 in fillers of rubber based on butyl rubber, instead of carbon black K354. The physicochemical properties of the samples of technical carbon under study, the results of physical and mechanical tests, and the gas permeability tests of rubber mixtures filled with the samples under study are presented. A conclusion is made about the possibility of replacing channel technical carbon K354 with furnace black carbon N121 oxidized with 30% hydrogen peroxide.

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