Factors impacting gas content measurements using gas desorption by drilling underground boreholes

Accurate determination of the gas content in coalbeds is important for safe mining. Currently, gas desorption by drilling underground boreholes is the most commonly used gas determination method. However, this method is not very accurate and needs to be improved. In this study, we established a labo...

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Main Authors: Zenghua Li, Qiangqiang Qi, Yongliang Yang, Yinbo Zhou, Bin Wang
Format: Article
Language:English
Published: SAGE Publishing 2016-10-01
Series:Adsorption Science & Technology
Online Access:https://doi.org/10.1177/0263617416664534
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author Zenghua Li
Qiangqiang Qi
Yongliang Yang
Yinbo Zhou
Bin Wang
author_facet Zenghua Li
Qiangqiang Qi
Yongliang Yang
Yinbo Zhou
Bin Wang
author_sort Zenghua Li
collection DOAJ
description Accurate determination of the gas content in coalbeds is important for safe mining. Currently, gas desorption by drilling underground boreholes is the most commonly used gas determination method. However, this method is not very accurate and needs to be improved. In this study, we established a laboratory protocol based on coal adsorption studies to analyse factors affecting the measurement accuracy. The results showed that exposure time, sampling method, sample weight, particle size and gas loss estimate significantly affected the gas content measurement using gas desorption by drilling underground boreholes. Longer exposure time and increased particle size resulted in higher relative errors. Sampling by coring is more accurate than sampling by drilling. The higher the sample weight is for samples weighing less than 240 g, the larger the error of the in situ measurements of desorbed gas, residual gas and lost gas is. The error tends to stabilize for heavier samples. The gas losses at different exposure times calculated using the commonly used Barrer model, power function method and negative exponent method were compared. The gas loss error within 0–12 min, computed with the Barrer model, and after 12 min, computed with the power function method, is minimal. The modified formula of gas loss was obtained using the combination of a fitting analysis and the relationship between gas loss and exposure time. Subsequently, the optimal procedure for in situ gas content measurements using gas desorption by drilling underground boreholes was determined. The gas content errors for anthracite, gas coal, lean coal and long flame coal, which were measured using gas desorption by drilling underground boreholes and corrected using the gas loss formula, decreased significantly to less than 10%, thus, meeting the engineering accuracy norm.
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institution Kabale University
issn 0263-6174
2048-4038
language English
publishDate 2016-10-01
publisher SAGE Publishing
record_format Article
series Adsorption Science & Technology
spelling doaj-art-9b40b38f16d44606b27bbb9fd12264a22025-01-02T02:59:13ZengSAGE PublishingAdsorption Science & Technology0263-61742048-40382016-10-013410.1177/0263617416664534Factors impacting gas content measurements using gas desorption by drilling underground boreholesZenghua LiQiangqiang QiYongliang YangYinbo ZhouBin WangAccurate determination of the gas content in coalbeds is important for safe mining. Currently, gas desorption by drilling underground boreholes is the most commonly used gas determination method. However, this method is not very accurate and needs to be improved. In this study, we established a laboratory protocol based on coal adsorption studies to analyse factors affecting the measurement accuracy. The results showed that exposure time, sampling method, sample weight, particle size and gas loss estimate significantly affected the gas content measurement using gas desorption by drilling underground boreholes. Longer exposure time and increased particle size resulted in higher relative errors. Sampling by coring is more accurate than sampling by drilling. The higher the sample weight is for samples weighing less than 240 g, the larger the error of the in situ measurements of desorbed gas, residual gas and lost gas is. The error tends to stabilize for heavier samples. The gas losses at different exposure times calculated using the commonly used Barrer model, power function method and negative exponent method were compared. The gas loss error within 0–12 min, computed with the Barrer model, and after 12 min, computed with the power function method, is minimal. The modified formula of gas loss was obtained using the combination of a fitting analysis and the relationship between gas loss and exposure time. Subsequently, the optimal procedure for in situ gas content measurements using gas desorption by drilling underground boreholes was determined. The gas content errors for anthracite, gas coal, lean coal and long flame coal, which were measured using gas desorption by drilling underground boreholes and corrected using the gas loss formula, decreased significantly to less than 10%, thus, meeting the engineering accuracy norm.https://doi.org/10.1177/0263617416664534
spellingShingle Zenghua Li
Qiangqiang Qi
Yongliang Yang
Yinbo Zhou
Bin Wang
Factors impacting gas content measurements using gas desorption by drilling underground boreholes
Adsorption Science & Technology
title Factors impacting gas content measurements using gas desorption by drilling underground boreholes
title_full Factors impacting gas content measurements using gas desorption by drilling underground boreholes
title_fullStr Factors impacting gas content measurements using gas desorption by drilling underground boreholes
title_full_unstemmed Factors impacting gas content measurements using gas desorption by drilling underground boreholes
title_short Factors impacting gas content measurements using gas desorption by drilling underground boreholes
title_sort factors impacting gas content measurements using gas desorption by drilling underground boreholes
url https://doi.org/10.1177/0263617416664534
work_keys_str_mv AT zenghuali factorsimpactinggascontentmeasurementsusinggasdesorptionbydrillingundergroundboreholes
AT qiangqiangqi factorsimpactinggascontentmeasurementsusinggasdesorptionbydrillingundergroundboreholes
AT yongliangyang factorsimpactinggascontentmeasurementsusinggasdesorptionbydrillingundergroundboreholes
AT yinbozhou factorsimpactinggascontentmeasurementsusinggasdesorptionbydrillingundergroundboreholes
AT binwang factorsimpactinggascontentmeasurementsusinggasdesorptionbydrillingundergroundboreholes