Study on effect of different injection source gases on CH4 adsorption diffusion behavior in coal

doi:10.16265/j.cnki.issn1003-3033.2025.02.0919

Abstract

Abstract:

To investigate the impact of different injection source gases on the adsorption and diffusion behavior of methane (CH₄) in coal, three types of gases were selected: hot gas power generation exhaust (heat injection, multi-component), carbon dioxide (CO₂) at room temperature (strong adsorption, single component), and nitrogen (N₂) at room temperature (weak adsorption, single component). Using giant canonical Monte Carlo (GCMM) and molecular dynamics (MD) methods, these gases were mixed with CH₄ and injected into coal to analyze the adsorption conditions. Based on a fixed amount of CH₄, the changes in diffusion behavior were analyzed after injecting each of the three gases. The results show that with the increase of gas injection ratio, the reduction of CH₄ adsorption capacity under CO₂ injection condition is gradually greater than that under thermal power generation tail gas condition, showing better inhibition performance than thermal power generation tail gas. In contrast, although the adsorption capacity of CH₄ decreases after N₂ injection, it is always greater than the previous two. In terms of diffusion, with the increase of gas injection ratio, the diffusion coefficient increases first and then decreases, and the coefficient is always larger than before gas injection, and the displacement gas mainly promotes CH₄ diffusion. Under N₂ injection, the diffusion coefficient of CH₄ is the highest and the decrease is the smallest, and the promoting effect is the most obvious. Under the condition of CO₂ injection, the diffusion coefficient of CH₄ decreases the most and the promoting effect is the weakest. Therefore, the selection of hot tail gas from gas-fired power generation for CH₄ displacement is more cost-effective.

Key words: CH₄, injection source gas, adsorption and diffusion behavior, diffusion coefficient, hot tail gas from gas-fired power generation

CLC Number:

X936

LI Linfei, LU Weidong, HUANG Ge, DAI Fengwei. Study on effect of different injection source gases on CH₄ adsorption diffusion behavior in coal[J]. China Safety Science Journal, 2025, 35(2): 175-185.

Figures/Tables 15

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References 32

[1]	门相勇, 娄钰, 王一兵, 等. 中国煤层气产业“十三五”以来发展成效与建议[J]. 天然气工业, 2022, 42(6):173-178.
	MEN Xiangyong, LOU Yu, WANG Yibing, et al. Development achievements and suggestions of China's coalbed methane industry since the 13^th Five-Year Plan[J]. Natural Gas Industry, 2022, 42(6): 173-178.
[2]	LONG Hang, LIN Haifei, YAN Min, et al. Adsorption and diffusion characteristics of CH₄, CO₂, and N₂ in micropores and mesopores of bituminous coal: molecular dynamics[J]. Fuel, 2021,292: DOI: 10.1016/j.fuel.2021.120268.
[3]	JESSEN K, TANG Guoqing, KOVSCEK A R. Laboratory and simulation investigation of enhanced coalbed methane recovery by gas injection[J]. Transport in Porous Media, 2008, 73: 141-159.
[4]	HAN Fengshuang, BUSCH A, KROOSS B M, et al. CH₄ and CO₂ sorption isotherms and kinetics for different size fractions of two coals[J]. Fuel, 2013, 108: 137-142.
[5]	ZHOU Fengde, HUSSAIN F, CHINAR Y. Injecting pure N₂ and CO₂ to coal for enhanced coalbed methane: experimental observations and numerical simulation[J]. International Journal of Coal Geology, 2013, 116: 53-62.
[6]	WANG Liguo, WANG Zhaofeng, LI Kaizhi, et al. Comparison of enhanced coalbed methane recovery by pure N₂ and CO₂ injection: experimental observations and numerical simulation[J]. Journal of Natural Gas Science and Engineering, 2015, 23: 363-372.
[7]	姜延航, 白刚, 周西华, 等. 煤层注CO₂驱替CH₄影响因素试验研究[J]. 中国安全科学学报, 2022, 32(4):113-121. doi: 10.16265/j.cnki.issn1003-3033.2022.04.017
	JIANG Yanhang, BAI Gang, ZHOU Xihua, et al. Experimental study on influencing factors of CO₂ injection for CH₄displacement in coal seam[J]. China Safety Science Journal, 2022, 32(4): 113-121. doi: 10.16265/j.cnki.issn1003-3033.2022.04.017
[8]	白刚, 姜延航, 周西华, 等. 不同CO₂注入温度置换驱替CH₄特性试验研究[J]. 煤炭科学技术, 2021, 49(5):167-174.
	BAI Gang, JIANG Yanhang, ZHOU Xihua, et al. Experimental study on displacement characteristics of CH₄ at different CO₂ injection temperatures[J]. Coal Science and Technology, 2021, 49(5): 167-174.
[9]	LI Shugang, BAI Yang, LIN Haifei, et al. Molecular simulation of adsorption of gas in coal slit model under the action of liquid nitrogen[J]. Fuel, 2019, 255: DOI: 10.1016/j.fuel.2019.115775.
[10]	MENG Zhuoyue, YANG Zhiyuan, YIN Zhiqiang, et al. Interaction between dispersant and coal slime added in semicoke water slurry: an experimental and DFT study[J]. Applied Surface Science, 2021, 540: DOI: 10.1016/j.apsusc.2020.148327.
[11]	BAI Yang, LIN Haifei, LI Shugang, et al. Molecular simulation of N₂ and CO₂ injection into a coal model containing adsorbed methane at different temperatures[J]. Energy, 2021, 219: DOI: 10.1016/j.energy.2020.119686.
[12]	JIA Jinzhang, WU Yumo, ZHAO Dan, et al. Adsorption of CH₄/CO₂/N₂ by different functional groups in coal[J]. Fuel, 2023, 335: DOI: 10.1016/j.fuel.2022.127062.
[13]	SONG Yu, JIANG Bo, LAN Fengjuan. Competitive adsorption of CO₂/N₂/CH₄ onto coal vitrinite macromolecular: effects of electrostatic interactions and oxygen functionalities[J]. Fuel, 2019, 235: 23-38.
[14]	DURUCAN S, SHI Jiquan. Improving the CO₂ well injectivity and enhanced coalbed methane production performance in coal seams[J]. International Journal of Coal Geology, 2009, 77(1/2): 214-221.
[15]	SHI Jiquan, DURUCAN S, FUJIOKA M. A reservoir simulation study of CO₂ injection and N₂ flooding at the Ishikari coalfield CO₂ storage pilot project, Japan[J]. International Journal of Greenhouse Gas Control, 2008, 2(1): 47-57.
[16]	SYED A, DURUCAN S, SHI Jiquan, et al. Flue gas injection for CO₂ storage and enhanced coalbed methane recovery: mixed gas sorption and swelling characteristics of coals[J]. Energy Procedia, 2013, 37: 6738-6745.
[17]	ZHOU Lijun, ZHOU Xihua, FAN Chunhua, et al. Modelling of flue gas injection promoted coal seam gas extraction incorporating heat-fluid-solid interactions[J]. Energy, 2023, 268: DOI: 10.1016/j.energy.2023.126664.
[18]	XING Wanli, LIU Yifan, ZHANG Wanli. Adsorption characteristics of CO₂/CH₄/N₂ ternary mixtures on anthracite from 293.15 to 353.15 K and pressures up to 7 MPa[J]. ACS omega, 2020, 5(19): 11 138-11 146.
[19]	WU Siyuan, DENG Cunbao, WANG Xuefeng. Molecular simulation of flue gas and CH₄ competitive adsorption in dry and wet coal[J]. Journal of Natural Gas Science and Engineering, 2019, 71: DOI: 10.1016/j.jngse.2019.102980.
[20]	TAO Tong, WANG Shitao, QU Yixin, et al. Displacement of shale gas confined in illite shale by flue gas: a molecular simulation study[J]. Chinese Journal of Chemical Engineering, 2021, 29(1): 295-303. doi: 10.1016/j.cjche.2020.09.015
[21]	GAO Dameng, HONG Lin, WANG Jiren, et al. Molecular simulation of gas adsorption characteristics and diffusion in micropores of lignite[J]. Fuel, 2020, 269: DOI: 10.1016/j.fuel.2020.117443.
[22]	WISER W H. Magnetic resonance: introduction, advanced topics and applications to fossil energy[M]. Dordrecht: Springer Netherlands, 1984: 325-350.
[23]	CARLSON G A. Computer simulation of the molecular structure of bituminous coal[J]. Energy & Fuels, 1992, 6(6): 771-778.
[24]	PENG Dingyu, ROBINSON D B. A new two-constant equation of state[J]. Industrial & Engineering Chemistry Fundamentals, 1976, 15(1): 59-64.
[25]	PINI R, OTTIGER S, BURLINI L, et al. Sorption of carbon dioxide, methane and nitrogen in dry coals at high pressure and moderate temperature[J]. International Journal of Greenhouse Gas Control, 2010, 4(1): 90-101.
[26]	ZHU Hongqing, WANG Wei, HUO Yujia, et al. Molecular simulation study on adsorption and diffusion behaviors of CO₂/N₂ in lignite[J]. ACS Omega, 2020, 5(45): 29 416-29 426.
[27]	YANG Jinzhi, LIU Qinglin, WANG Haitao. Analyzing adsorption and diffusion behaviors of ethanol/water through silicalite membranes by molecular simulation[J]. Journal of Membrane Science, 2007, 291(1/2): 1-9.
[28]	周西华, 韩明旭, 白刚, 等. CO₂注气压力对瓦斯扩散系数影响规律实验研究[J]. 煤田地质与勘探, 2021, 49(1):81-86,99.
	ZHOU Xihua, HAN Mingxu, BAI Gang, et al. Experimental study on the influence of CO₂ injection pressure on gas diffusion coefficient[J]. Coal Geology & Exploration, 2021, 49(1): 81-86,99.
[29]	XU Hao, TANG Dazhen, ZHAO Jiaxin, et al. A new laboratory method for accurate measurement of the methane diffusion coefficient and its influencing factors in the coal matrix[J]. Fuel, 2015, 158: 239-247.
[30]	杨宏民, 张铁岗, 王兆丰, 等. 煤层注氮驱替甲烷促排瓦斯的试验研究[J]. 煤炭学报, 2010, 35(5):792-796.
	YANG Hongmin, ZHANG Tiegang, WANG Zhaofeng, et al. Experimental study on nitrogen injection for methane displacement and gas removal in coal seam[J]. Journal of China Coal Society, 2010, 35(5): 792-796.
[31]	唐巨鹏, 邱于曼, 马圆. 煤中CH₄扩散影响因素的分子动力学分析[J]. 煤炭科学技术, 2021, 49(2):85-92.
	TANG Jupeng, QIU Yuman, MA Yuan. Molecular dynamics analysis of influencing factors of CH₄ diffusion in coal[J]. Coal Science and Technology, 2021, 49(2): 85-92.
[32]	聂尧, 赵越超. 煤中多组分混合气体竞争吸附研究现状及工程应用[J]. 矿业科学学报, 2020, 5(1):45-57.
	NIE Yao, ZHAO Yuechao. Research status and engineering application of competitive adsorption of multicomponent gas mixtures in coal[J]. Journal of Mining Science, 2020, 5(1): 45-57.

p/kPa	注源气体积分数ω/%	p/kPa
p/kPa		尾气组分					单组分
CH₄		CO₂	O₂	NO₂	NO	CO	N₂	CO₂	N₂
90	10	0.655	0.941	0.001	0.002	0.004	8.397	10	10
80	20	1.31	1.882	0.002	0.004	0.008	16.794	20	20
70	30	1.965	2.823	0.003	0.006	0.012	25.191	30	30
60	40	2.62	3.764	0.004	0.008	0.016	33.588	40	40
50	50	3.275	4.705	0.005	0.01	0.020	41.985	50	50
40	60	3.93	5.646	0.006	0.012	0.024	50.382	60	60
30	70	4.585	6.587	0.007	0.014	0.028	58.779	70	70
20	80	5.25	7.528	0.008	0.016	0.032	67.176	80	80
10	90	5.895	8.469	0.009	0.018	0.036	75.573	90	90

ω/%	拟合方程lnD	E_a/(kJ·mol^-1)	R²
0	-1 290.76T^-1+4.40	10.73	0.875
10	-304.67T^-1+1.98	2.53	0.887
20	-310.17T^-1+1.98	2.58	0.939
30	-328.67T^-1+2.03	2.73	0.967
40	-347.09T^-1+2.06	2.89	0.858
50	-364.56T^-1+2.09	3.03	0.871
60	-403.30T^-1+2.16	3.35	0.905
70	-558.50T^-1+2.63	4.64	0.975
80	-769.37T^-1+3.27	6.40	0.937
90	-1205.15T^-1+4.63	10.02	0.883

Study on effect of different injection source gases on CH₄ adsorption diffusion behavior in coal

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