Effect of soluble organic matter on the low-temperature oxidation of coal.

In order to reveal the soluble organic matter effect on the spontaneous combustion of coal, the infrared spectroscopy and GC/MS experiments were used to test the changes of coal surface microstructure and product ingredients after extracted by tetrahydrofuran. Based on the results of soluble organic matter affect the pore structure of the coal, and according to the gas-product release law of low temperature oxidation of coal before and after the extraction, effect of soluble organic matter of the coal on surfactant structure and low temperature characters of coal oxidation was discussed. The results indicate that after extraction, the content of hydroxyl and carboxyl in residual coal is reduced. Meantime, mineral content and active side chains and functional groups which involve high-content oxygen in coal also reduce. Coal soluble organic matter contains a large amount of the active groups, such as methyl, hydroxyl, carbonyl and ether etc. The total pore volume and surface area of the residual coal is increased in varying degrees. The average pore size of residual coal reduces from 6. 3 nm to 4. 9 nm. The oxygen consumption of extracted residual coal in low-temperature oxidation stage is significantly lower than that of raw coal, and CO, CO2, C2H4 and C2H6 gas emission reduced than raw coal to some extend. The soluble organic matter in coal promotes the spontaneous combustion of coal. [ABSTRACT FROM AUTHOR]