A method of removing carbon dioxide from flue gas is disclosed. The method comprises mixing the flue gas with ammonia; and contacting the gas mixture with calcium nitrate solution to produce calcium carbonate precipitates and ammonium nitrate solution; or contacting the gas mixture with sodium nitrate solution to produce sodium carbonate precipitates and ammonium nitrate solution. The carbonate/bicarbonate precipitates are recovered by separating the carbonate/bicarbonates (s) from said solutions. An apparatus for performing the above method is also disclosed. The apparatus comprises a reaction vessel with an inlet to receive said solution and an inlet to receive and deliver a flue gas-ammonia mixture to a gas-liquid contactor which is configured to diffuse said gas mixture into either calcium nitrate or sodium nitrate solution. The reaction vessel is also provided with an impellor and draft tube configured to circulate the diffused gas mixture throughout the calcium nitrate or sodium nitrate solution for a period of time sufficient to produce carbonate/bicarbonate precipitates locking the CO2 into a solid form.

A method of removing carbon dioxide from flue gas is disclosed. The method comprises mixing the flue gas with ammonia; and contacting the gas mixture with calcium nitrate solution to produce calcium carbonate precipitates and ammonium nitrate solution; or contacting the gas mixture with sodium nitrate solution to produce sodium carbonate precipitates and ammonium nitrate solution. The carbonate/bicarbonate precipitates are recovered by separating the carbonate/bicarbonates (s) from said solutions. An apparatus for performing the above method is also disclosed. The apparatus comprises a reaction vessel with an inlet to receive said solution and an inlet to receive and deliver a flue gas-ammonia mixture to a gas-liquid contactor which is configured to diffuse said gas mixture into either calcium nitrate or sodium nitrate solution. The reaction vessel is also provided with an impellor and draft tube configured to circulate the diffused gas mixture throughout the calcium nitrate or sodium nitrate solution for a period of time sufficient to produce carbonate/bicarbonate precipitates locking the CO2 into a solid form.

A gassing reactor is provided that comprises a dispersion stage with a rotor and a stator. The rotor and the stator respectively exhibit at least one shear surface that exhibits at least one axial component in relation to the axis of rotation of the dispersion stage. It is further provided that the gassing reactor exhibits at least one gas feed line that opens into at least one gas outlet opening into a dispersion gap of the dispersion stage formed between the rotor and the stator, delimited by the shear surfaces. In this way, the gas introduction into the liquid can be done within a range in which the maximum shear forces and highly-turbulent shear fields occurs when the gassing reactor is operating and rotor is rotating. This promotes a reliable as a fine-beaded as possible dissipation of the gas into the liquid.

A method and apparatus for injecting a gas into a liquid in which a rotating helical impeller within a draft tube submerged in the liquid creates a liquid flow within the draft tube. Gas bubbles are injected into the draft tube either above or below or alongside the helical impeller or in all three locations. The liquid is drawn into the draft tube with a superficial velocity greater than a substantially uniform terminal ascent velocity of the gas bubbles to allow entrainment of undissolved gas bubbles in the bulk liquid into the liquid being drawn into the draft tube. The gas bubbles are injected with a uniform diameter of between about 10.0 microns and about 1.0 millimeters. The small bubble size enhances the dissolution of the gas into the liquid and also allow the entrainment of the gas into the liquid being drawn into the draft tube.

A method and apparatus for injecting a gas into a liquid in which a rotating helical impeller within a draft tube submerged in the liquid creates a liquid flow within the draft tube. Gas bubbles are injected into the draft tube either above or below or alongside the helical impeller or in all three locations. The liquid is drawn into the draft tube with a superficial velocity greater than a substantially uniform terminal ascent velocity of the gas bubbles to allow entrainment of undissolved gas bubbles in the bulk liquid into the liquid being drawn into the draft tube. The gas bubbles are injected with a uniform diameter of between about 10.0 microns and about 1.0 millimeters. The small bubble size enhances the dissolution of the gas into the liquid and also allow the entrainment of the gas into the liquid being drawn into the draft tube.

The present invention is in the field of stirring, and particularly relates to a stirring assembly including a rotary shaft and a stirring member. The stirring member is fixedly provided on the rotary shaft. The rotary shaft is provided with a first passage therein. The first passage is formed with an air inlet through one end of the rotary shaft. The stirring member is provided with a second passage therein. The second passage is formed with an air outlet through the stirring member. The second passage is connected with the first passage. In the present invention, when the rotary shaft is rotating, the external air is drawn in from the air inlet and discharged from the air outlet to make the liquid to be mixed by the stirring member with the air discharged from the air outlet.