METHOD AND DEVICE FOR BUILDING UNDERGROUND STOREHOUSE BY DISSOLVING LIMESTONE WITH CARBON DIOXIDE

摘要

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 CO₂ gas having at least 1 MPa of pressure into a CO₂ absorbing solution having the same pressure to form a CO₂ solution, flowing the CO₂ 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 CO₂, water and calcium carbonate, and recycling the separated CO₂ absorption solution and the CO₂; 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 CO₂ 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).