Effect of degassing temperature on nitrogen adsorption of three rank coals
颜志丰沈军平李丹张振国高莲凤宋清宇孙明晓
YAN Zhifeng,SHEN Junping,LI Dan,ZHANG Zhenguo,GAO Lianfeng, SONG Qingyu,SUN Mingxiao
辽宁工程技术大学 矿业学院河北工程大学 地球科学与工程学院
低温氮吸附实验是研究煤储层孔隙的重要方法,通过实验得到的数据能表征出煤孔隙结 构。 低温氮吸附实验结果受到样品粒径、脱气温度和脱气时间等因素的影响,其中脱气温度和脱气 时间受到样品本身性质影响较大且不易控制。 为研究低温氮吸附实验中脱气温度对结果的影响, 选取北宿矿的中变质烟煤、马兰矿的高变质烟煤和新景矿的无烟煤 3 种不同变质程度的煤样进行 低温氮吸附实验。 实验过程中采用相同的脱气处理时间,时间长度均为 2 h,脱气处理温度分别为 105,120,135,150 °C。 据此研究煤样在不同脱气温度下孔隙结构的变化,并对实验结果的差异性 进行分析。 通过分析 3 种煤阶的煤样在相同脱气时间和不同脱气温度条件下的质量变化率、吸附 等温线、吸附量、孔容、孔比表面积和平均孔径等参数,发现不同煤阶的煤样当脱气温度发生变化 时,实验结果相应发生变化。 通过实验发现在改变脱气温度时,影响煤孔隙结构实验结果的主要因 素是煤中的水分和挥发分。 随着脱气温度的升高,实验结果受水分的影响逐渐变弱,受挥发分的影 响逐渐增强。 在相同脱气时间和脱气温度的条件下,煤的变质程度越高,实验结果受水分的影响就 越小。 在脱气时间为 2 h 的情况下,煤样的脱气温度建议为 135 °C 。 低变质程度的煤由于挥发分 很高,对温度更加敏感,是不是遵循相同的规律还需要进行探讨。
Low temperature nitrogen adsorption experiment is an important method to study the pore of a coal reservoir. The pore structure of coal can be characterized by the experimental data. The results of lowtemperature nitrogen adsorption experiment are affected by some factors such as sample particle size,degassing temperature,and degassing time. Among these factors,the degassing temperature and degassing time are greatly affected by the nature of the sample and are not easy to be controlled. In order to study the effect of degassing temperature on the results of the lowtemperature nitrogen adsorption experiment,three kinds of coal samples with different metamorphic degrees were used for the lowtemperature nitrogen adsorption experiment,including the medium metamorphic bituminous coal of Beisu mine,the high metamorphic bituminous coal of Malan Mine and the anthracite of Xinjing Mine. The same degassing treatment time was used in the experiment,the time length was 2 hours,and the degassing treatment temperatures were 105,120,135,150 ℃ respectively. By analyzing the parameters such as mass change rate,adsorption isotherm,adsorption capacity,porevolume,porespecific surface area and average pore diameter of three ranking coal samples under the same degassing time and different degassing temperatures,it is found that the experimental results of coal samples with different coal ranks also change when the degassing temperature changes. Also,it is found that the main factors affecting the experimental results of coal pore structure are water and volatile in coal when changing the degassing temperature. With the increase in degassing temperature,the experimental results are gradually weakened by water and enhanced by volatile matter. Under the same degassing time and degassing temperature,the higher the degree of coal metamorphism,the less the influence of water on the experimental results. When the degassing time is 2 hours,the degassing temperature of the coal sample is recommended to be 135 ℃. Low metamorphic coal is more sensitive to temperature because of its high volatile content. Whether it follows the same law needs to be further studied.
不同变质程度不同温度低温氮吸附倒“ S” 分布孔隙结构
different metamorphic degree;different temperature;low temperature nitrogen adsorption;inverted “S” distribution;pore structure
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会