scholarly journals The Effect of Pore Volume of Hard Coals on Their Susceptibility to Spontaneous Combustion

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Agnieszka Dudzińska
Keyword(s):  
Carbon Dioxide ◽  
Porous Structure ◽  
Pore Volume ◽  
Oxygen Diffusion ◽  
Spontaneous Combustion ◽  
Gas Adsorption ◽  
Experimental Studies ◽  
Carbon Dioxide Adsorption ◽  
Adsorption Method

In this paper the results of the experimental studies on a relationship between pore volume of hard coals and their tendency to spontaneous combustion are presented. Pore volumes were determined by the gas adsorption method and spontaneous combustion tendencies of coals were evaluated by determination of the spontaneous combustion indexesSzaandSza′on the basis of the current Polish standards. An increase in the spontaneous combustion susceptibility of coal occurs in the case of the rise both in micropore volumes and in macropore surfaces. Porosity of coal strongly affects the possibility of oxygen diffusion into the micropores of coal located inside its porous structure. The volume of coal micropores determined on the basis of the carbon dioxide adsorption isotherms can serve as an indicator of a susceptibility of coal to spontaneous combustion.

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).

Influence of intramolecular interactions on carbon dioxide gas adsorption capacity in Mesoporous Imine polymers

2018 ◽  
Author(s):  
Jaya Prakash Madda ◽  
Pilli Govindaiah ◽  
Sushant Kumar Jena ◽  
Sabbhavat Krishna ◽  
Rupak Kishor
Keyword(s):  
Carbon Dioxide ◽  
Adsorption Capacity ◽  
Density Functional ◽  
Gas Adsorption ◽  
Ambient Pressure ◽  
Condensation Reaction ◽  
Intramolecular Interactions ◽  
Carbon Dioxide Adsorption ◽  
Nitrogen Gas ◽  
Adsorption Characteristic

<p>Covalent organic Imine polymers with intrinsic meso-porosity were synthesized by condensation reaction between 4,4-diamino diphenyl methane and (para/meta/ortho)-phthaladehyde. Even though these polymers were synthesized from precursors of bis-bis covalent link mode, the bulk materials were micrometer size particles with intrinsic mesoporous enables nitrogen as well as carbon dioxide adsorption in the void spaces. These polymers were showed stability up to 260<sup>o</sup> centigrade. Nitrogen gas adsorption capacity up to 250 cc/g in the ambient pressure was observed with type III adsorption characteristic nature. Carbon dioxide adsorption experiments reveal the possible terminal amine functional group to carbamate with CO<sub>2</sub> gas molecule to the polymers. One of the imine polymers, COP-3 showed more carbon dioxide sorption capacity and isosteric heat of adsorption (Q<sub>st</sub>) than COP-1 and COP-2 at 273 K even though COP-3 had lower porosity for nitrogen gas than COP-1 and COP-2. We explained the trends in gas adsorption capacities and Qst values as a consequence of the intra molecular interactions confirmed by Density Functional Theory computational experiments on small molecular fragments.</p>

Porphyrin-based porous polyimides: Synthesis, porous structure, carbon dioxide adsorption

Polymer ◽  
2019 ◽  
Vol 169 ◽  
pp. 160-166 ◽  
Author(s):  
Kaixiang Shi ◽  
Ningning Song ◽  
Yongcun Zou ◽  
Shiyang Zhu ◽  
Haiwei Tan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Porous Structure ◽  
Carbon Dioxide Adsorption

Carbon dioxide adsorption on doped boron nitride nanotubes

RSC Advances ◽  
2014 ◽  
Vol 4 (54) ◽  
pp. 28249-28258 ◽  
Author(s):  
Edson N. C. Paura ◽  
Wiliam F. da Cunha ◽  
João Batista Lopes Martins ◽  
Geraldo Magela e Silva ◽  
Luiz F. Roncaratti ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Boron Nitride ◽  
Adsorption Process ◽  
Gas Adsorption ◽  
Boron Nitride Nanotubes ◽  
Carbon Dioxide Adsorption

Boron nitride nanotubes are promising structures as far as gas adsorption process is concerned.

Influence of intramolecular interactions on carbon dioxide gas adsorption capacity in Mesoporous Imine polymers

2018 ◽  
Author(s):  
Jaya Prakash Madda ◽  
Pilli Govindaiah ◽  
Sushant Kumar Jena ◽  
Sabbhavat Krishna ◽  
Rupak Kishor
Keyword(s):  
Carbon Dioxide ◽  
Adsorption Capacity ◽  
Density Functional ◽  
Gas Adsorption ◽  
Ambient Pressure ◽  
Condensation Reaction ◽  
Intramolecular Interactions ◽  
Carbon Dioxide Adsorption ◽  
Nitrogen Gas ◽  
Adsorption Characteristic

<p>Covalent organic Imine polymers with intrinsic meso-porosity were synthesized by condensation reaction between 4,4-diamino diphenyl methane and (para/meta/ortho)-phthaladehyde. Even though these polymers were synthesized from precursors of bis-bis covalent link mode, the bulk materials were micrometer size particles with intrinsic mesoporous enables nitrogen as well as carbon dioxide adsorption in the void spaces. These polymers were showed stability up to 260<sup>o</sup> centigrade. Nitrogen gas adsorption capacity up to 250 cc/g in the ambient pressure was observed with type III adsorption characteristic nature. Carbon dioxide adsorption experiments reveal the possible terminal amine functional group to carbamate with CO<sub>2</sub> gas molecule to the polymers. One of the imine polymers, COP-3 showed more carbon dioxide sorption capacity and isosteric heat of adsorption (Q<sub>st</sub>) than COP-1 and COP-2 at 273 K even though COP-3 had lower porosity for nitrogen gas than COP-1 and COP-2. We explained the trends in gas adsorption capacities and Qst values as a consequence of the intra molecular interactions confirmed by Density Functional Theory computational experiments on small molecular fragments.</p>

Effects of extraction process on the dried cell wall pore structure of messmate heartwood

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6074-6082
Author(s):  
Weikai Wang ◽  
Minghan Li ◽  
Jiabin Cai
Keyword(s):  
Cell Wall ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Extraction Process ◽  
Micropore Volume ◽  
Adsorption Method

In order to study the effects of a messmate heartwood extraction process on its cell wall pore structure and its drying ability, its nanopore structure was explored after via gas adsorption technology. Specifically, the messmate heartwood particles were extracted with methanol, and then the cell wall pore structure of the original and extracted samples were evaluated by N2 and CO2 sorption and pycnometer methods, respectively. Overall, compared with the original samples, the cell wall porosity, micropore volume, mesopore volume, BET specific surface area, and specific surface area of the micropores of the extracted messmate heartwoods increased by 2.55%, 0.007 cm3/g, 0.0014 cm3/g, 0.24 m2·g-1, and 21.9 m2·g-1, respectively. The cell wall pore volume measured via the gas adsorption method was smaller than the measurement from the pycnometer method. The results indicated that the presence of extractives made the messmate cell wall have a decreased pore volume and porosity, which may be one of the reasons messmate wood is difficult to dry. Messmate extractives primarily were present in the micropores of the cell wall in the range of 0.4 nm to 0.7 nm. However, gas sorption technology could not detect all the pores in the cell wall of the messmate heartwood sample.

The Influence of Coal Adsorbing Methane and Carbon Dioxide on Gas Outburst

2014 ◽  
Vol 1049-1050 ◽  
pp. 101-104 ◽  
Author(s):  
De Zhu Cheng ◽  
Ai Ling Du ◽  
Ai Qin Du
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Langmuir Isotherm ◽  
Gas Adsorption ◽  
Good Description ◽  
Methane Adsorption ◽  
Pulverized Coal ◽  
Carbon Dioxide Adsorption ◽  
Adsorption Experiment ◽  
Anthracite Coal

Methane and carbon dioxide of different pressures were absorbed by the anthracite coal for 5 hours in high pressure reactor. When adsorption experiment was completed, pressure is reduced quickly. The content of pulverized coal which was produced by releasing gas quickly, was used to reflect capacity of gas adsorption. The result showed that the content of pulverized coal which was produced by adsorbing CH4 was higher than that was produced by adsorbing CO2 on the same coal under the same pressure. Langmuir isotherm and Freundlich isothermal can describe coal methane adsorption. Freundlich isothermal can be a good description of coal carbon dioxide adsorption.

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