Abstract
Methane has caused the most disastrous mine accidents throughout the history of mining because of its flammable and explosible nature. Methane is a process gas occurred during the coalification process together with the coal substance from the decomposition of organic materials. Typically, as the thickness and the depth of coal seams increase, the gas retained within the coal and the surrounding strata also increases. Most of the methane gas retained by coal micropores in adsorbed state are released to the atmosphere as soon as mining activities starts due to the higher gas pressure available and increased permeabilities around mine openings. In order to take necessary measures against methane explosions in underground coal mining, it is necessary to determine the actual gas content of coal seams. In this study, a new design for gas measuring capsules (canisters) in direct gas measurement technique was made and then it was manufactured. The designed system was used to determine the gas content of coal samples taken from underground coal mines located in Gediz and Tavşanlı districts of Kütahya province. After the preliminary tests, it was realized that gas content of coal seams could be measured as close as to the in-situ values using the extra facilities of the canister designed and the sampling technique proposed. As a result of the experiments, it was determined that the Gediz samples had an average gas content of 0.30 m3/ton, and the Tavşanlı samples had an average gas content of 0.63 m3/ton, on as-received basis and under standard temperature and pressure conditions.