Prognosticating fire hazards in goafs in Polish collieries

Zarębska, Katarzyna; Baran, Paweł; Cygankiewicz, J.; Dudzińska, Agnieszka

doi:10.7494/drill.2012.29.4.463

Cited by 9 publications

(10 citation statements)

References 17 publications

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“…A significant problem in forecasting fire based on the gas content in the mine is that propylene and ethylene may also subject to sorption on coal. Numerous studies have demonstrated that the above gases flowing through the coal seam may become trapped by physical or chemical sorption in the coal porous structure [11][12][13]. The sorption process refers to the phenomenon occurring at the solid-gas interface.…”

Section: Introductionmentioning

confidence: 99%

Research on a Gas Index Reflecting the Sorption Process on Carbon Materials in Coal Mines

Wojtacha‐Rychter

Smoliński

2018

Sustainability

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Based on the concentration of gases such as propylene and ethylene in the atmosphere of a mine, it is possible to assess the development of a mine fire. With the increase of coal temperature, an increased emission of these gases has been observed. However, the experiment results presented in this paper prove that the use of propylene and ethylene for the prediction of the spontaneous combustion of coal have some limitations. It was found that during a flow of gas mixture through the sorption column, propylene and ethylene were sorbed on coal. This phenomenon manifests in smaller amounts of gases at the outlet of the sorption column. By comparing the concentration of ethylene to propylene at the inlet of the column, it was concluded that the ratio was usually below 3, whereas the range of the ratio at the end of the column was between 0.6–353. The value of gases ratio changed depending on the type of coal material in the column. The results of this experiment provide useful information that the quantitative relation between ethylene and propylene concentrations may indicate the occurrence of the sorption process on carbon materials in coal seams.

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Section: Introductionmentioning

confidence: 99%

Research on a Gas Index Reflecting the Sorption Process on Carbon Materials in Coal Mines

Wojtacha‐Rychter

Smoliński

2018

Sustainability

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“…That indicates that coalbeds sharing these properties are useless in the context of potential CO 2 sequestration, which is broadly described in the literature as CO 2 storage in a deep saline aquifer. − However, in the case of coalbeds, most publications on the subject of CO 2 sequestration (in the area of experimental testing) are focused on sorption tests and establishing the influence of relevant parameters (coal rank, maceral content, porosity, and moisture content) on sorption capacity. In most cases, sorption tests are performed on grainy samples or on samples in the dust form. − This approach makes the experimental procedure less time-consuming (the sorption equilibrium is promptly established), although a question arises whether the sample crushing should not destroy the porous structure, and hence, the experimental results may not be directly related to the conditions prevailing in situ . In the case of coal expansion tests, the samples to be tested must not be crushed.…”

Section: Introductionmentioning

confidence: 99%

Expansion of Hard Coal Accompanying the Sorption of Methane and Carbon Dioxide in Isothermal and Non-isothermal Processes

2015

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Coal swelling because of methane and carbon dioxide was measured by the volumetric method in isothermal and non-isothermal conditions. These investigations are of key importance in the context of potential CO2 sequestration in deep unmined coalbeds. Changes of the temperature underground may disturb the adsorption balance, leading to volumetric processes in the coal strata (swelling or shrinking), which can give rise to leaks and gas desorption toward the ground surface. The isothermal results show that the strain exhibited by a coal sample during CO2 sorption is about twice that of CH4. The liner strain kinetics also show that the swelling of the sample when exposed to both gases is anisotropic and greater in the direction perpendicular to the bedding plane than parallel to it. In the case of the non-isothermal process, the pattern of dilatometric processes seems to be different. The temperature increase gives rise to the sample swelling when exposed to methane, yet the presence of CO2 leads to sample contraction, which can be attributed to the different mechanisms involved in CO2 deposition. CO2 accumulated in pores undergoes a rapid phase transition as a result of capillary condensation, leading to rapid desorption and, in consequence, shrinking of the coal sample.

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“…Coal is a porous material of highly developed inner surface and presence of micro- and sub-micropores, enabling sorption of vapors and gases. − Gases released in the process of coal self-heating adsorb on coal while migrating through workings. The resulting concentrations measured in mine air are underestimated, which may negatively affect the assessment of the fire hazard.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Sorption and Desorption of Propylene on Polish Hard Coals

2015

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Propylene is the unsaturated hydrocarbon emitted to the atmosphere of a coal mine in the process of coal selfheating. Its concentration in mine air is one of the indicators for the assessment of the development of the process of coal selfheating. Coal sorption capacities with respect to propylene may be the reason for the decrease in its concentration in mine air. This may affect the accuracy of the assessment of the self-heating process development, in particular, in the case of coals of considerable sorption capacities. The paper presents the results of coal sorption capacities with respect to propylene performed on 10 samples of bituminous coals acquired from operated coal seams. The sorption capacities of tested coal samples varied depending upon level of metamorphism, porosity, and chemical characteristics of a coal surface. The highest sorption capacities were reported for high-porosity coals of easily accessible pore structure, high specific surface area values, low level of metamorphism, and high oxygen content. The interactions between the electron-donor (and electron-acceptor) centers and π bond between the carbon atoms of the gaseous reactant probably play the most important role in the sorption of propylene on coals. Coals of low oxygen content, nonpolar surface structure, low porosity, and compact internal structure are characterized by low propylene sorption capacity. The results of the experimental study also indicate the partially irreversible character of the sorption process reflected in the open isotherm hysteresis. Some amount of propylene molecules remains in the coal structure, depending upon the coal properties and the experimental conditions applied.

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Prognosticating fire hazards in goafs in Polish collieries

Cited by 9 publications

References 17 publications

Research on a Gas Index Reflecting the Sorption Process on Carbon Materials in Coal Mines

Research on a Gas Index Reflecting the Sorption Process on Carbon Materials in Coal Mines

Expansion of Hard Coal Accompanying the Sorption of Methane and Carbon Dioxide in Isothermal and Non-isothermal Processes

Experimental Study on Sorption and Desorption of Propylene on Polish Hard Coals

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