scholarly journals Determination of methane content and methane released when exploiting longwall at different levels at 13.2 seams, Khe Cham coal mine, Vietnam

2020 ◽  
Vol 211 ◽  
pp. 03017
Author(s):  
Van Thinh Nguyen
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Methane Emissions ◽  
Methane Content ◽  
Methane Drainage ◽  
Gas Explosions ◽  
Two Factors ◽  
The Relationship ◽  
Different Levels

Khe Cham coal mine is managed by Ha Long Coal Company TKV. Currently, Khe Cham coal mine is exploited from the ground up to 350 and is ranked III for methane. In 2008, a methane explosion at -168 level of the 13.2 coal seam of Khe Cham coal mine occurred, injuring 16 people and killing 8. In order to avoid gas explosions at mines like 2008, it is necessary to have appropriate solutions to eliminate methane accumulation in the pit paths. We have studied to determine the relationship between the level of methane emissions with the methane content in the coal seam and the bazaar’s mining output because of the methane content in the coal seam and coal mining output. These are the two factors that greatly affect the release of methane from the longwall. The paper used practical measurement, sampling, and analysis methods to determine the level of methane emissions from longwalls at different extraction levels of the 13.2 coal seam and determine the relationship between the methane drainage and the methane content in the coal seam and the exploitation output of the longwall. This relationship is expressed by the equation y = a.x2 + b.x + c (Fig. 2 and Fig. 3). The results will help with planning for mining and have specific solutions for diluting methane in the mine’s pit lines

scholarly journals DETERMINATION OF METHANE DESORPTION ZONE FOR THE DESIGN OF A DRAINAGE BOREHOLE PATTERN (CASE STUDY: E4 PANEL OF THE TABAS MECHANIZED COAL MINE, IRAN)

2021 ◽  
Vol 36 (1) ◽  
pp. 61-75
Author(s):  
Ali Hosseini ◽  
Mehdi Najafi
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Coal Mine ◽  
Methane Emissions ◽  
Gas Content ◽  
Coal Seams ◽  
Mining Operations ◽  
Methane Drainage ◽  
Tabas Coal Mine ◽  
Drainage Borehole

Underground coal mining is known as one of the major sources of methane emissions which mainly occurs after underground coal extraction. Rock strata in-situ methane can potentially be the most significant hazard in coal mining operations. To prevent or minimize the risks of methane emissions, methane drainage approaches have been adopted by coal mines. Rock mass methane drainage is the most efficient and effective approach toward controlling methane hazards as it prevents and reduces the frequency of methane emissions, outflows into the working area and sudden outbursts of methane and rocks. The method includes drilling boreholes from the tailgate side to the unstressed zone in the roof and floor strata above and below a working coal seam. The coal seam gas content in Tabas Parvadeh I is estimated to be about 16 m3 /t, which is relatively high. Based on exploration data, five distinct coal seams have been identified (B1, B2, C1, C2 and D) at the coal deposit and currently C1 is being worked. Considering the high value of C1 gas content and surrounding rocks, the Methane Drainage System (MDS) has been utilized for gas drainage. This paper tries to determine the desorption area which is essential and helpful for the selection of an effective drilling pattern into the adjacent coal seams. In this study, the methane drainage zone in the E4 panel of the Tabas coal mine was calculated using experimental equations and a drainage borehole pattern was determined.

Study on the Relationship of the Quantity of CO2 Produced and the Wind Speed

2014 ◽  
Vol 881-883 ◽  
pp. 1638-1641
Author(s):  
Xian Long Sun ◽  
Er Xin Gao ◽  
Hong Fen Zhang ◽  
Qiang Wang ◽  
Li Juan Li
Keyword(s):  
Experimental Data ◽  
Wind Speed ◽  
Coal Seam ◽  
Coal Mine ◽  
Laboratory Experiments ◽  
Spontaneous Combustion ◽  
Geothermal Heat ◽  
Research Results ◽  
Relationship Of ◽  
The Relationship

Based on the geological and the experimental data of the13#coal seam of Sun-Cun Coal Mine, the relationship curve between the geothermal heat in Sun-Cun coal mine and experimental wind speed has been fit out.According this and the laboratory experiments,the relational expression between the quantity of CO2 produced in the period of spontaneous combustion and the wind speed in the coal mine has been developed. The research results show that when the wind speed exceeds 2m/s,the quantity of CO2 produced has a sharp rising tendency.

Coal Mine Methane Drainage and Comprehensive Utilization in China

2013 ◽  
Vol 295-298 ◽  
pp. 3023-3026 ◽  
Author(s):  
Qing Ye ◽  
Yan Pi ◽  
Zhen Zhen Jia ◽  
Hai Zhen Wang
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Chemical Production ◽  
Efficient Utilization ◽  
Effective Utilization ◽  
Coal Mine Methane ◽  
Development Stages ◽  
Methane Drainage ◽  
Coal Seam Methane ◽  
Methane Utilization

According to situation of coal mine methane drainage and utilization, the five experienced development stages of coal mine methane drainage technology was summarized, the reasons of low rate of coal mine methane drainage were analyzed. Coal-seam methane utilization was analyzed from methane purification, methane generating electricity, chemical production, methane for civil utilization and utilization as automobile fuel etc. With the coal seam methane drainage quantity is more and more, the emissions requirements is more and more strict, so the emission reduction and effective utilization of this energy is important to accelerate efficient utilization of coal methane, reduce greenhouse gas emissions, protect environment, alleviate the supply contradiction of energy and realize sustainable development of coal mine etc.

scholarly journals Determination of cyclic filling length in gob-side entry retained with roadside filling and its application

2020 ◽  
Author(s):  
Zizheng Zhang ◽  
Jianbiao Bai ◽  
Xianyang Yu ◽  
Weijian Yu ◽  
Min Deng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Difference Method ◽  
Suggested Method ◽  
Stress Difference ◽  
Thick Coal Seam ◽  
Mechanics Model ◽  
Working Face ◽  
Geological Conditions ◽  
The Relationship

Abstract Gob-side entry retained with roadside filling (GER-RF) plays a key role in achieving coal mining without pillar and improving the coal resource recovery rate. Since there are few reports on the cyclic filling length of GER-RF, a method based on the stress difference method is proposed to determine the cyclic filling length of GER-RF. Firstly, a stability analysis mechanics model of the immediate roof above roadside filling area in GER was established, then the relationship between the roof stress distribution and the unsupported roof length was obtained by the stress difference method. According to the roof stability above roadside filling area based on the relationship between the roof stress and its tensile strength, the maximum unsupported roof length and rational cyclic filling length of GER-RF. Combined with the geological conditions of the 1103 thin coal seam working face of Heilong Coal Mine and the geological conditions of the 1301 thick coal seam working face of Licun Coal Mine, this suggested method was applied to determine that the rational cyclic filling lengths of GER-RF were 2.4 m and 3.2 m, respectively. Field trial tests show that the suggested method can effectively control the surrounding rock deformation along with rational road-in support and roadside support, and improve the filling and construction speed.

The Relationship between the Period of Spontaneous Combustion and the Wind Speed

2014 ◽  
Vol 496-500 ◽  
pp. 613-616
Author(s):  
Xian Long Sun ◽  
Er Xin Gao ◽  
Qiang Wang ◽  
Shan Shan Xu ◽  
Chun Yuan Li
Keyword(s):  
Experimental Data ◽  
Wind Speed ◽  
Coal Seam ◽  
Coal Mine ◽  
Coal Sample ◽  
Laboratory Experiments ◽  
Spontaneous Combustion ◽  
Geothermal Heat ◽  
Research Results ◽  
The Relationship

Based on the geological and the experimental data of the 13# coal seam of Sun-Cun Coal Mine, the relationship curve between the geothermal heat in Sun-Cun coal mine and experimental wind speed has been fit out. According this and the laboratory experiments, the relational expression between the period of spontaneous combustion in coal sample and the wind speed has been developed. The research results show that the curve of wind speed and the spontaneous combustion period fitted quadratic polynomial forms.

scholarly journals Calculation of permeability coefficient of coal seam under rapid measurement conditions

2019 ◽  
Vol 136 ◽  
pp. 04004
Author(s):  
Manzheng Yang ◽  
Bingrui Li ◽  
Shubo Li
Keyword(s):  
Coal Seam ◽  
Permeability Coefficient ◽  
Integral Transformation ◽  
Gas Permeability ◽  
Rapid Determination ◽  
Flow State ◽  
Time Curve ◽  
Pressure Time ◽  
The Relationship

In order to achieve rapid determination of coal seam permeability, the calculation method of coal seam permeability coefficient was studied. Based on the Darcy's law in the flow of gas in the coal seam, the relationship equation between the gas pressure of the borehole and the gas permeability coefficient of the coal seam is established under the radial unsteady flow state. The gas permeability coefficient of the coal seam is obtained by coordinate transformation and integral transformation. Solve the expression. The analysis and verification of the field measured data show that the expression of the analytical solution of the coal seam permeability coefficient is consistent with the variation of the borehole pressure-time curve, which can provide a theoretical basis for the rapid determination of coal seam permeability.

scholarly journals The Combustion of Methane from Hard Coal Seams in Gas Engines as a Technology Leading to Reducing Greenhouse Gas Emissions—Electricity Prediction Using ANN

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4429
Author(s):  
Marek Borowski ◽  
Piotr Życzkowski ◽  
Jianwei Cheng ◽  
Rafał Łuczak ◽  
Klaudia Zwolińska
Keyword(s):  
Coal Seam ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Coal Mine ◽  
Electricity Production ◽  
Hard Coal ◽  
Neural Network Models ◽  
Gas Emissions ◽  
Methane Drainage ◽  
Geological Conditions

Greenhouse gases such as carbon dioxide and methane cause global warming and consequently climate change. Great efforts are being made to reduce greenhouse gas emissions with the objective of addressing this problem, hence the popularity of technologies conductive to reducing greenhouse gas emissions. CO2 emissions can be reduced by improving the thermal efficiency of combustion engines, for example, by using cogeneration systems. Coal mine methane (CMM) emerges due to mining activities as methane released from the coal and surrounding rock strata. The amount of methane produced is primarily influenced by the productivity of the coal mine and the gassiness of the coal seam. The gassiness of the formation around the coal seam and geological conditions are also important. Methane can be extracted to the surface using methane drainage installations and along with ventilation air. The large amounts of methane captured by methane drainage installations can be used for energy production. This article presents a quarterly summary of the hourly values of methane capture, its concentration in the methane–air mixture, and electricity production in the cogeneration system for electricity and heat production. On this basis, neural network models have been proposed in order to predict electricity production based on known values of methane capture, its concentration, pressure, and parameters determining the time and day of the week. A prediction model has been established on the basis of a multilayer perceptron network (MLP).

Analysis of Coal Mine Methane Development Technology in China

2013 ◽  
Vol 868 ◽  
pp. 326-330
Author(s):  
Xin Sun ◽  
Bai Sheng Nie ◽  
Sheng Chu Huang ◽  
Shou Tao Hu
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Coal Bed ◽  
Pressure Relief ◽  
Coal Mine Methane ◽  
Methane Drainage ◽  
Soft Coal ◽  
Methane Extraction ◽  
Development Technology ◽  
Soft Coal Seam

This paper introduces occurrence characteristics of coal bed methane in China, and analyses the influence of coal seam permeability on coal mine methane extraction. In addition, it presents the mechanism of increasing permeability by pressure relief. Lastly, the methane extraction technologies are discussed, and the applicable conditions of these technologies are analyzed. It is seen that choosing appropriate methane drainage technology, often in combination with several technologies including ground drilling, underground drilling, and pressure relief and permeability improving measures, is crucial for geological complex coal seam, especially low permeability soft coal seam.

scholarly journals Estimation of Gas Loss in Methodology for Determining Methane Content of Coal Seams

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 982
Author(s):  
Nikodem Szlązak ◽  
Dariusz Obracaj ◽  
Marek Korzec
Keyword(s):  
Coal Seam ◽  
Coal Sample ◽  
Uniform Method ◽  
Methane Content ◽  
Gas Content ◽  
National Standard ◽  
Desorption Rate ◽  
Coal Seams ◽  
Gas Loss

The determination of natural gas content in coal seams is essential to safe mining activities and to estimate gas resources. It is used to estimate methane emissions into workings, which is very important when using preventive measures of methane ignition and explosion. Methane content in a coal seam is mostly determined using a direct method. However, a problem with estimation of gas loss during collecting a sample in a mine occurs in each method. That gas loss is estimated using different procedures. In the Polish mining industry, methane content in a coal seam is mostly determined during roadway advancing faces in coal seams. The differences in procedures for determining methane content in coal in various laboratories gave rise to starting research into developing a new method. This article presents results of study of gas loss unification for the determination of methane content in coal seams. The research focused mainly on determining a uniform method for estimating gas loss using the early adsorption diffusion process. The method of coal sample saturation with methane was used to measure gas desorption rate. Saturation pressures of samples were determined for coal seams in the Upper-Silesian Coal Basin. The analysis of desorption results allowed to determine the dependence between methane content in a coal sample and the initial methane content in a coal seam. It was concluded that the desorption rate was highest within two minutes. For the procedure of coal sampling, gas loss was determined at 12% of both desorbed and residual gases. The presented research results gave rise to developing a uniform method for determining gas content used in Polish coal mining. The method was accepted as the national standard. Methodology using a new gas loss estimation procedure allows for achieving relatively fast results of the determination of methane content in coal seams, which is very important, especially in gassy mines.

Study on the Relation between the Deep and the Spontaneous Combustion of Coal Seam

2014 ◽  
Vol 852 ◽  
pp. 821-825 ◽  
Author(s):  
Jian You Di ◽  
Er Xin Gao ◽  
Xian Long Sun ◽  
Chang Qing Sun ◽  
Yu Li Chen
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Laboratory Experiments ◽  
Spontaneous Combustion ◽  
Geothermal Gradient ◽  
Laboratory Analysis ◽  
Spontaneous Combustion Of Coal ◽  
Mine Depth ◽  
Relationship Of ◽  
The Relationship

Based on the data and laboratory analysis of Sun-Cun Coal Mine, the relationship between the geothermal gradient and the depth of mine in Suncun Coal Mine has been developed. According to this and the laboratory experiments, the relationship between spontaneous combustion period of coal seam and the depth of the mine has been obtained in this article. The results show that the law of coal seam spontaneous combustion period and the mine depth in accordance with the relationship of the gauss curve expression and when the coal mine depth is around 1000 m, the coal seam spontaneous combustion period shortened dramatically. This law should be pay more attention to.

Sign in / Sign up

Export Citation Format

Share Document