METHOD FOR DISPOSAL OF CARBON DIOXIDE (CO) FROM UNDERGROUND-COAL-GASIFICATION-DERIVED GAS (UCG-DERIVED GAS) Russian patent published in 2014 - IPC E21B43/295 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to mining and can be used for underground coal gasification. The method lies in division of CO₂ received in the surface chemical complex into two flows: the first flow is injected into blast injection holes of the operating underground gas generator and endothermic chemical reaction CO₂+C=2CO-q is initiated in gasification zones thus enriching UCG-derived gas with combustible CO component; the second flow of CO₂ is injected into depleted underground gas generator. At that quantity of CO₂ injected to the operating underground gas generator is determined depending on temperature level in gasification oxidising zone and composition of the gas extracted from the neighbouring well. Bottom-ash mass of the depleted underground gas generator is saturated with lime hydrate aqueous solution [Ca(OH)₂], to that end it is injected into wells of the depleted underground gas generator until concentration of this solution is stabilised which is proven by periodical solution sampling and chemical analysis of that. When concentration of lime hydrate is stabilised in analysed samples the second CO₂ flow is injected into wells of the depleted gas generator for the purpose of its chemical absorption. Injection of CO₂ is stopped to the depleted gas generator when its concentration in periodic samples increases up to 90%.

EFFECT: technical result is obtained through complete disposal of CO₂ in UCG-derived gas.

5 cl, 2 dwg