夏大平, 廖佳佳, 王心义,等.不同CO₂压力下黄铁矿与煤制气耦合机制研究[J].河南理工大学学报（自然科学版）,doi:10.16186/j.cnki.1673-9787.2023020065

XIA D P, LIAO J J, WANG X Y, et al.Study on the coupling mechanism between pyrite and coal to gas under different CO₂ pressure conditions[J].Journal of Henan Polytechnic University(Natural Science) ,doi:10.16186/j.cnki.1673-9787.2023020065

不同CO₂压力下黄铁矿与煤制气耦合机制研究(网络首发)

夏大平1,2,3, 廖佳佳1, 王心义1,2,3, 李赛赛4, 顾朋涛4, 袁筱莹1, 简阔5

1.河南理工大学 资源环境学院，河南 焦作 454000;2.河南理工大学 煤炭安全生产与清洁高效利用省部共建协同创新中心，河南 焦作  454000;3.河南理工大学 矿业研究院，河南 焦作 454000;4.河南理工大学 能源科学与工程学院，河南 焦作  454000;5.太原科技大学 能源 与材料工程学院，山西 晋城  048011

摘要:为研究不同CO₂压力下黄铁矿与煤制气耦合机制，利用设置压力为1，3，5 MPa的高压罐 进行煤和黄铁矿厌氧发酵产气试验。结果表明：（1）压力为1 MPa时产气量较好，最终产气量 为1.26 mmol/g；压力增加，罐中产气量减少，压力为5 MPa时产气量仅0.02 mmol/g ；（ 2）随着压 力增加，水溶液中质量浓度和氧化还原电位（Eh）逐渐上升，pH逐渐下降，5 MPa试验组 反应末期pH最低，为4.02，1 MPa压力罐内总铁有消耗，波动较大，3 MPa和5 MPa压力罐中总 铁浓度持续增加，说明3 MPa和5 MPa压力下黄铁矿溶解量增加较多；（3）化学需氧量（chemical oxygen deman，COD）和短链脂肪酸浓度随压力增加逐渐降低，反映了厌氧发酵程度的降低 和黄铁矿酸化强度的增强；（4）压力增加，功能菌种丰度和多样性降低，硫铁菌属逐渐处于优势 地位，厌氧发酵过程基本停滞。研究结果可为原位条件富集营养液注入后的产气机制研究提 供理论支撑。

关键词:CO2压力;煤生物产气;黄铁矿;总铁;酸化程度

中图分类号：P618.11　

doi:10.16186/j.cnki.1673-9787.2023020065

基金项目:国家自然科学基金资助项目（42230804，42172199，42102218）；河南省创新型科技人才队伍建设工程项目 （CXTD2016053）；河南省优秀青年科学基金资助项目（202300410168）；中国石油集团公司“十四五”前瞻性基础性技术攻 关课题（2021DJ2302）

收稿日期:2023-02-22

修回日期:2023-04-06

网络首发日期: 2023-06-25

Study on the coupling mechanism between pyrite and coal to gas under different CO₂ pressure conditions(Online)

XIA Daping1,2,3, LIAO Jiajia1, WANG Xinyi1,2,3, LI Saisai4, GU Pengtao4, YUAN Xiaoying1, JIAN Kuo5

1.Institute of Resources & Environment，Henan Polytechnic University，Jiaozuo  454000，Henan，China;2.Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization，Jiaozuo  454000，Henan，China;3.Mining Research Institute，Henan Polytechnic University，Ji- aozuo  454000，Henan，China;4.School of Energy Science and Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China;5.College of Energy and Materials Engineering，Taiyuan University of Science and Technology，Jincheng  048011，Shanxi，China

Abstract:The in situ biogasification utilisation of coal can be affected by a variety of factors. Pyrite, as a common mineral fraction in coal seams and top and bottom plates, is likely to be involved in the anaerobic fermentation process when enriched bacterial solution is injected, and there is a lot of free gas in the coal seams. In order to study the effect of anaerobic fermentation of coal involving pyrite under different CO₂ pressure conditions, anaerobic fermentation gas production experiments of coal and pyrite were designed for three pressure autoclaves at 1, 3 and 5 MPa, and the results showed that: (1) the gas production was better at the pressure of 1 MPa, which was 1.26 mmol/L,with the increase of CO₂ pressure, the gas production decreased faster, and the gas production at 5 MPa was only 0.02 mmol/L, basically no output. (2) With the increase of pressure, the  concentration gradually increased, and the total iron was consumed in 1MPa with large fluctuations, while the total iron concentration kept increasing in 3 MPa  and 5 MPa, indicating that the dissolved amount of pyrite increased more in the latter two, and was positively correlated with the  concentration. (3) As the reaction progressed, the pH value kept decreasing, with the lowest value appearing at the end of the reaction at 5 MPa at 4.02, while the Eh value gradually increased; the COD value and short-chain fatty acid content also gradually decreased with the increase in pressure, which also reflected the decrease in the degree of anaerobic fermentation and the increase in the intensity of pyrite acidification. The study of anaerobic fermentation of coal under pyrite and different CO₂ pressure conditions can provide good theoretical support for an in-depth understanding of the gas production mechanism during nutrient enrichment injection under in situ conditions.

Key words:pressure;coal biogenic gas production;pyrite;total iron;degree of acidification

CLC: P618.11