无烟煤瓦斯解吸的块度效应及其电化学作用效果研究

发布时间：2018-05-15 06:02

本文选题：无烟煤 + 块度　；参考：《太原理工大学》2013年硕士论文

【摘要】：我国在煤层气开采领域还处于起步阶段,各项技术还不够成熟,尤其是我国煤田地质特殊的“三低一高”特征所引起煤层低解吸、低渗透等问题,一直是制约煤层气开采的重点问题。因此,提高瓦斯在煤层中的解吸率和渗透率,改进抽采技术,成为我国煤层气开采的关键环节。本文首先详细地分析了国内外对煤瓦斯解吸特性和电化学对煤作用的研究现状,提出了一种非力学作用煤体提高煤层瓦斯解吸的方法,即电化学强化煤层瓦斯解吸的基本研究思想和理论,并进行了以下主要的研究工作： 1、在自主研制块煤瓦斯吸附解吸装置上对0.8mm～1mm、8mm～10mm、20mm～25mm、40mm～45mm、70mm～75mm和135mm～140mm六种块度的无烟煤进行了不同瓦斯吸附平衡压力下的等温气体解吸试验。 2、在自主研制的块煤电化学作用装置上对上述六种块度的无烟煤进行了电化学改性试验。 3、通过对六种块度自然无烟煤瓦斯的解吸数据分析,得出随着无烟煤的块度增大,解吸速率及解吸率逐渐减小、解吸平衡时间逐渐延长；随着瓦斯吸附压力的增加,煤瓦斯解吸的能力逐渐增强,但解吸的增加率逐渐减小。 4、通过对六种块度电化学改性无烟煤瓦斯的解吸数据分析,得出电化学作用后块度为0.8mm～1mm的无烟煤解吸速率大于其他五类块度煤样解吸速率,而随块度的增大煤样解吸速率逐渐降低但差别不明显；电化学作用后无烟煤瓦斯解吸特性仍与瓦斯吸附压力有关：随着瓦斯吸附压力的增加,煤瓦斯解吸的能力逐渐增强,但瓦斯吸附压力为2MPa和3MPa下,解吸效果变化不明显。 5、通过对六种块度电化学改性前后无烟煤瓦斯的解吸数据分析,得出块度为0.8mm～1mm的无烟煤经电化学作用后解吸速率变化不明显,而其他块度煤样电化学作用后解吸速率均有所提高并且块度越大解吸速率增加越明显；块度为0.8mm～1mm的无烟煤经电化学作用后解吸率明显降低,其余五种块度无烟煤样经电化学作用后解吸率均有所提高。 6、通过对0.8mm～1mm和8mm～10mm两种块度自然无烟煤的压汞数据分析,得出块度为8mm～10mm煤样的中孔及大孔所占比例比0.8mm～1mm块度煤样的明显增多,说明大块度的煤样中微孔及小孔所占比例下降；0.8mm～1mm和8mm～10mm两种块度无烟煤样的比表面积分别为1.330m2/g和6.415m2/g,说明大块度煤样的比表面积大大增加。分析认为：无烟煤瓦斯解吸速率可能由煤样中中孔及大孔的数量决定；而无烟煤的比表面积则决定了其瓦斯解吸率的大小。 7、通过对原无烟煤样、0.8mm～1mm块度改性无烟煤样和8mm～10mm块度改性无烟煤样的FTIR图谱分析,得出电化学处理后无烟煤的醇、酚、醚、酯等含氧官能团的迅速减少是导致电化学作用后无烟煤瓦斯解吸率提高的直接原因；而0.8mm～1mm和8mm～10mm两种块度改性煤样的图谱曲线差别不明显,说明随着改性煤样块度的增大,电化学对无烟煤影响作用减小,宏观上表现为随着块度的增加,瓦斯解吸率逐渐降低,但降低幅度逐渐减小。
[Abstract]:China is still in the initial stage in the field of coal seam gas mining, and the technology is not mature enough. Especially, the special "three low and one high" characteristics of coal geology in our country causes low desorption and low permeability of coal seam, which has always been the key problem to restrict the mining of coal bed gas. Therefore, it is necessary to improve the desorption rate and permeability of gas in the coal seam and improve the extraction of coal seam. Technology has become the key link of coal seam gas mining in China. Firstly, this paper analyzes the research status of coal gas desorption characteristics and the effect of electrochemistry on coal at home and abroad, and puts forward a method of improving coal seam gas desorption by non mechanical coal body, that is the basic research thought and theory of electrochemical enhancement of coal seam gas desorption. The following main research work:
1, the isothermal gas desorption test was carried out on six blocks of 0.8mm ~ 1mm, 8mm to 10mm, 20mm to 25mm, 40mm to 45mm, 70mm to 75mm and 135mm to 140mm, on the self developed coal gas adsorption and desorption device.
2, electrochemical modification experiments of six kinds of anthracite were carried out on the independently developed block electrochemistry device.
3, through the analysis of the desorption data of six kinds of natural anthracite coal gas, it is concluded that the desorption rate and desorption rate gradually decrease with the increase of the bulk of the anthracite coal, and the desorption equilibrium time is gradually extended. With the increase of gas adsorption pressure, the ability of coal gas desorption is gradually enhanced, but the increase rate of desorption is gradually reduced.
4, by analyzing the desorption data of six kinds of electrochemical modified anthracite coal gas, it is concluded that the desorption rate of the anthracite with a degree of 0.8mm ~ 1mm after electrochemical action is greater than that of the other five kinds of lump coal sample desorption rate, and the desorption rate of coal sample decreases with the increase of the lump degree, but the difference is not obvious; the gas desorption of anthracite after the electrochemical action is not obvious. The characteristics of gas adsorption pressure are still related to gas adsorption pressure: with the increase of gas adsorption pressure, the ability of coal gas desorption is gradually enhanced, but the adsorption pressure of gas is 2MPa and 3MPa, and the effect of desorption is not obvious.
5, through the analysis of the desorption data of the anthracite gas before and after the six block electrochemical modification, it is concluded that the desorption rate of the anthracite with the bulk of 0.8mm ~ 1mm is not obvious after the electrochemical action, but the desorption rate of the other lump coal samples increases and the greater the bulk density is, the greater the bulk density is 0.8mm ~ 2. The desorption rate of 1mm anthracite decreased obviously after electrochemical treatment, and the desorption rate of the other five kinds of anthracite samples increased after electrochemical treatment.
6, through the analysis of the mercury pressure data of two kinds of natural anthracite from 0.8mm to 1mm and 8mm to 10mm, it is found that the proportion of the middle hole and the large hole in the 8mm to 10mm coal sample is more than the 0.8mm to 1mm lump coal samples, which indicates that the proportion of the micropores and small holes in the large lump coal samples decreases; 0.8mm to 1mm and 8mm to 10mm two kinds of block anthracite samples The specific surface area of the coal sample is 1.330m2/g and 6.415m2/g, respectively, indicating that the specific surface area of the large lump coal is greatly increased. It is believed that the gas desorption rate of anthracite may be determined by the number of mesoporous and large pores in the coal samples, while the specific surface area of anthracite coal determines the large fraction of its gas desorption rate.
7, through the analysis of the FTIR Atlas of the anthracite samples, 0.8mm to 1mm block modified anthracite samples and 8mm to 10mm block modified anthracite samples, the rapid reduction of oxygen containing functional groups such as alcohol, phenol, ether and ester after electrochemical treatment is the direct cause of the increase of the desorption rate of anthracite after electrochemical action; and 0.8mm to 1mm and 8mm. The difference of the atlas curves of two kinds of coal samples modified by 10mm is not obvious. It shows that the effect of electrochemical on anthracite coal decreases with the increase of the size of the modified coal sample, and the gas desorption rate gradually decreases with the increase of the block degree, but the decrease is gradually reduced.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TD712

【参考文献】