ABSTRACT

Coal spontaneous combustion indicator gases are one of the important indicators to judge coal spontaneous combustion, but coal spontaneous combustion is not the only source of these gases, the coal will also absorb these gases. Therefore, the study of gas adsorption characteristics in coal is of great significance for the prevention of coal fire. In this work, the adsorption characteristics of the low concentrations of carbon monoxide (CO), carbon dioxide (CO₂) and methane (CH₄) in coal were studied and the competitive adsorption relationships among these three gases were identified by sorption isotherms. Experiments were performed on two coal samples from the Linnancang Coal Mine (LNC coal sample, named after the first word of the mine name) and Xixizhuang Coal Mine (XXZ coal sample, same as above), which were submitted to different gas atmosphere. A mathematical approach for calculating the adsorptive volume of each gas component under four experimental conditions was proposed, and the relationship between the adsorption capacities of CO, CO₂ and CH₄ and pressure was obtained during the adsorption and desorption. The results show that for the XXZ coal sample, the adsorption volume of CO under the maximum pressure conditions during the standard gas adsorption and desorption process is 7.7×10⁻² mL/g, while the comparable values in gas-He, gas-CH₄ and gas-CO₂ are 3.5×10⁻² mL/g, 1.9×10⁻² mL/g, and 1.2×10⁻² mL/g, respectively. The adsorption volumes of CO, CO₂ and CH₄ decrease with increasing pressure, but the decreasing trend is lower than that of standard gas adsorption under low-concentration conditions. The adsorption capacity of the desorption process under the same pressure conditions is greater than that of the adsorption process. In the adsorption state composed of CO, CO₂, and CH₄ gases, there are mutual constraints and influences between the gases, showing competitive adsorption behavior. Both CO₂ and CH₄ have obvious inhibitory effects on CO, while He does not inhibit CO adsorption.

摘要

煤自燃指标气体是判断煤自燃的重要指标之一，但煤自燃不是这些气体的唯一来源，煤也会吸收这些气体。因此，研究煤中的瓦斯吸附特性对预防煤着火具有重要意义。在这项工作中，低浓度的一氧化碳（CO），二氧化碳（CO ₂）和甲烷（CH ₄）在煤中进行了研究，并通过吸附等温线确定了这三种气体之间的竞争吸附关系。对临南苍煤矿（LNC煤样，以矿名的第一个名字命名）和西溪庄煤矿（XXZ煤样，同上）的两个煤样进行了试验，并分别将其送入不同的瓦斯气氛。提出了在四种实验条件下计算每种气体组分吸附量的数学方法，并探讨了CO，CO ₂和CH ₄的吸附容量之间的关系。在吸附和解吸过程中获得压力。结果表明，对于XXZ煤样，在标准气体吸附和解吸过程中，在最大压力条件下CO的吸附量为7.7×10 ^-2 mL / g，而在气体-氦气，气体-甲烷中的可​​比值₄和gas-CO ₂分别为3.5×10 ^-2 mL / g，1.9×10 ^-2 mL / g和1.2×10 ^-2 mL / g。CO，CO ₂和CH ₄的吸附量随压力增加而降低，但降低趋势低于低浓度条件下标准气体吸附的下降趋势。在相同压力条件下，解吸过程的吸附能力大于吸附过程。在由CO，CO ₂和CH ₄气体组成的吸附状态下，气体之间存在相互制约和影响，表现出竞争性的吸附行为。CO ₂和CH ₄对CO都有明显的抑制作用，而He却不抑制CO的吸附。