Purpose. For gasification of coal reserves concentrated in off-balance sheet and balance sheet reserves with a focus on obtaining combustible gases as a substitute for natural gas.
Specifications. The formation of active zones and thermal intensification of the reaction channel of the gas generator is ensured by reversing the supply of blast from the blast wells and gas outlets. The fire face is located in the temperature range of 695 – 1004 °C. The average supply pressure of the blast mixture is 0.24 MPa. This allows the formation of oxidation and reduction zones of the gas generator. At the same time, the optimal speed of advance in the fire face (1.8 – 2.5 m/day) ensures a balance between the oxidative (27 – 32%) and reduction (73 – 68%) zones of chemical reactions along the length of the fire face. Destabilization of the gasification process occurs when the oxidizing zone advances relative to the reducing zone by more than 50%. The introduction of reverse levels the fire face and activates gasification processes, creating effective conditions for the occurrence of physical and chemical processes. The heat of combustion of combustible generator gases increases by 54–61% and amounts to almost 7 MJ/m3.
Application area. Mining industry enterprises.
Advantages. There is a known method for underground gasification of solid fuel, which involves preparing a mine gas generator with long columns along a layer of solid fuel, which are outlined with horizontal wells from mine workings, forming a reaction channel from the berm of the workings, which connects the horizontal wells on which they are mounted. connecting wells to the reaction channel [Patent RU 89276, E21B 43/295, 01/11/2010]. At the same time, the main disadvantage of this method is the significant cost of constructing a special chamber in a mine opening for mounting a guide device and a winding drum, which, using this technology, excludes the construction of the above chamber.
Technical and economic effect. The proposed technology for gasification of off-balance and on-balance coal reserves will reduce socio-economic tension in mining areas, creating about 50 additional jobs per production well, which, in turn, will lead to the replenishment of budgets at various levels by 2 million 11 thousand 11 thousand UAH in a year. The use of the proposed technology will ensure gasification of local and/or substandard coal reserves. At the speed of advance of one fire face (1.8 – 2.5 m/day), depending on the thickness of the coal seam (0.8 – 1.2 m), the mass of gasified coal will be (84 – 90 tons). The average yield of generator gas from one ton of coal is 2.2 thousand m3. When the concentration of methane gas in the generator gas is 12-26%, its volume will be 22.0-49.5 thousand m3, which can be deposited up to 137.5-310.3 m3 of hydrate.
Description. The proposed technology for gasification of coal reserves, which is concentrated in off-balance sheet and on-balance coal reserves through the introduction of new technological operations, ensures the practical maneuverability of fire faces and the uniformity of their progress in the underground space with the production of a high-quality energy product (generator gas).