Zhang Qiang, Li Chenwei, Guangxin Xue, Zhang Baoyong, Liu Chuanhai
Department of Safety Engineering, Heilongjiang University of Science and Technology, No. 2468 Puyuan Road, Songbei District, Harbin 150022, Heilongjiang, China.
National Central Laboratory of Hydrocarbon Gas Transportation Pipeline Safety, Harbin 150022, Heilongjiang, China.
ACS Omega. 2020 Dec 29;6(1):786-798. doi: 10.1021/acsomega.0c05378. eCollection 2021 Jan 12.
In the process of coal mining, gas outburst is a challenge that must be prevented to guarantee mining safety. Forming gas hydrate in coal can reduce the original gas pressure and delay the concentrative outbursts of gas flow, which is one of the potential technologies to prevent gas outbursts in coal. In this work, we perform the formation and dissociation kinetics experiment of hydrate in the presence of coal and tetrahydrofuran (THF) at the temperature based on different geological conditions in China by means of the experimental device with the impedance measurement function. The results showed that the impedance change can qualitatively describe the kinetic characteristics of hydrate formation and dissociation in coal. The sudden change in pressure and system impedance during gas hydrate formation indicated the nucleation point at which hydrate formation started, by which the induction time can be acquired. Pressure and impedance suddenly changed at the same time, which implied that methane molecules and tetrahydrofuran (THF) molecules entered the hydrate phase at the same time. When the dissociation temperature increased to 303.15 K, the hydrate dissociation rate can be less affected by dissociation temperature if it continued to increase. This work highlights that gas hydrate formation in coal can effectively prevent gas outbursts.
在煤炭开采过程中，瓦斯突出是保障开采安全必须预防的一项挑战。在煤中形成天然气水合物可以降低原始瓦斯压力并延缓瓦斯流的集中突出，这是预防煤中瓦斯突出的潜在技术之一。在这项工作中，我们借助具有阻抗测量功能的实验装置，在中国不同地质条件下的温度下，进行了在煤和四氢呋喃（THF）存在下的水合物生成和解离动力学实验。结果表明，阻抗变化可以定性地描述煤中水合物生成和解离的动力学特征。天然气水合物生成过程中压力和系统阻抗的突然变化表明了水合物开始生成的成核点，据此可以获得诱导时间。压力和阻抗同时突然变化，这意味着甲烷分子和四氢呋喃（THF）分子同时进入水合物相。当解离温度升高到303.15 K时，如果继续升高，水合物解离速率受解离温度的影响较小。这项工作突出了煤中天然气水合物的形成可以有效预防瓦斯突出。
