Experimental study on the law of CO production in coal seam drilling

Abstract

Drilling operation is widely used in modern coal mine operation.Carbon monoxide gas (CO) is produced in coal seam during drilling operation, which leads to fire and CO exceeding accident.In this paper, an experimental platform for monitoring CO in coal borehole is built and Fourier infrared spectroscopy is carried out to analyze the law of production CO in coal seam during drilling from macroscopic and microscopic perspectives.The experimental results show that there is a certain amount of CO generated in the coal seam drilling operation, and the production of CO is proportional to the speed and temperature of the drill bit.In the coal sample cuttings after drilling, the contents of aliphatic group and oxygen-containing functional group are higher than the raw coal, indicating that the production rate of CO is higher than the consumption rate.Analysis shows that the CO produced during drilling operation is a mixture of oxidized carbon monoxide (O-CO) and carbon monoxide (S-CO) produced by the cracking of coal macromolecules.Among them, the O-CO generated during drilling operation mainly comes from oxygen-containing functional groups formed by oxidation of aliphatic functional groups such as -CH2 and -CH3, and pyrolysis occurs under the action of internal energy.S-CO is caused by coal's macromolecular fracture and the conversion of mechanical energy to thermal energy, leading to the pyrolysis of oxygen-containing functional groups in raw coal.

Keywords

• drilling
• co
• rotate speed
• temperature
• ftir
• functional groups