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).

主权项

1. A method for construction of an underground reservoir by dissolving limestone using carbon dioxide, the method comprising the steps of:
a) drilling a first well and a second well extending from a ground to a limestone layer, disposing at least one channel (5) in the limestone layer to connect the first well and the second well, and inserting a first sleeve (3) and a second sleeve (4) in the first well and the second well, respectively; b) introducing carbon dioxide having a gas pressure of at least 1 MPa into a carbon dioxide absorption solution having a pressure of at least 1 MPa to yield a carbon dioxide solution, injecting the carbon dioxide solution into the first sleeve (3) and allowing the carbon dioxide solution to flow to the limestone layer through the first sleeve (3) and react with limestone to yield a calcium bicarbonate containing solution whereby forming a cavern comprising solutions, and discharging the calcium bicarbonate containing solution out of the second sleeve (4); c) collecting and decompressing the discharged calcium bicarbonate containing solution so that calcium bicarbonate therein is decomposed to yield carbon dioxide, water, and calcium carbonate, performing a gas, liquid, and solid separation, collecting the separated carbon dioxide absorption solution for a new round of dissolution of carbon dioxide, collecting the separated carbon dioxide for a new round of formation of the carbon dioxide solution, and storing the separated calcium carbonate; and d) repeating steps b) and c) until a desired cavern comprising solutions is produced, discharging the solutions in the cavern to yield the underground reservoir.