| abstract |
A method for building an underground storehouse by dissolving limestone with carbon dioxide, the method comprising the following steps: a.) drilling two wells extending from the ground surface ( 1 ) to a limestone layer ( 2 ), building a channel ( 5 ) allowing the two wells to communicate, and installing casing pipes ( 3, 4 ) respectively in the two wells; b.) introducing CO 2 gas having at least 1 MPa of pressure into a CO 2 absorbing solution having the same pressure to form a CO 2 solution, flowing the CO 2 solution into underground via the casing pipe ( 3 ) to react with the limestone to form a calcium bicarbonate solution, forming a cavern in the meanwhile, and discharging the calcium bicarbonate solution via the other casing pipe ( 4 ); c.) decompressing the discharged calcium bicarbonate solution to decompose the calcium bicarbonate contained in the solution into CO 2 , water and calcium carbonate, and recycling the separated CO 2 absorption solution and the CO 2 ; repeating steps b.) and c.) until a cavern meeting design requirements is formed, and discharging the solution from the cavern to form the underground storehouse ( 6 ). Also disclosed is a device for building an underground storehouse by dissolving limestone with carbon dioxide, the device comprising a CO 2 storage tank ( 7 ), an absorption tower ( 8 ), a crystallizer ( 11 ), a pressure relief valve ( 9 ), a gas-liquid separator ( 10 ), a vacuum pump ( 13 ), a buffer ( 14 ) and booster pumps ( 12, 15, 16 ). |