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US 12,390,762 B1Granted
Plant and method to improve the efficiency of CO2 capture and storage using precipitated calcium carbonate
AssigneeLimenet S.R.L. Societa' Benefit
InventorGiovanni Cappello
Life of this patent
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Abstract
A plant and a method to improve the efficiency of CO2 capture and storage from the atmospheric air, using precipitated calcium carbonate (PCC) and calcium bicarbonates. The plant includes an electric calciner, a contactor, an apparatus for pH correction, a dosing device for the buffering substance, an absorber/precipitator, a separator, and a PCC dosing device. The system is suitable for receiving at the inlet electric energy, carbonate, water, a flow of atmospheric air and for releasing a flow of CO2-lean air, a buffered ionic mixture, and a flow of excess PCC. The plant uses the bicarbonates or carbonates as permanent CO2 storage: this storage allows a cost-effective CO2 storage in modular plants.
Claims10
A plant to improve the efficiency of CO2 capture and storage using precipitated calcium carbonate PCC, the plant comprising:
- an electric calciner, a contactor, an apparatus for pH correction, a dosing device for the buffering substance, an absorber/precipitator, a separator, and a PCC dosing device, wherein:
- the electric calciner is configured for receiving at the inlet a flow of carbonate, a flow of electric energy and for releasing at the outlet at least a flow of carbonic gas and at least a flow of oxide;
- the flow of oxide is configured for providing a flow of buffering substance, and a flow of alkaline substance;
- the contactor is configured for receiving at the inlet the flow of carbonic gas released by the electric calciner, a flow of dosed PCC and a flow of water;
- the contactor is further configured for reacting the CO2 present in the flow of carbonic gas with the flow of water and the flow of dosed PCC coming from the PCC dosing device according to the reactions:
- CO2(aq)+H2O(l)H2CO3(aq)H(aq)++HCO3(aq)−and
- CaCO3(s)+CO2(aq)+H2O→Ca(HCO3)2(aq)
- and for releasing at the outlet at least a flow of ionic mixture and a flow of non-soluble gases;
- the apparatus for pH correction is configured for receiving at the inlet at least a flow of buffering substance and the flow of ionic mixture;
- the apparatus for pH correction is configured for reacting the flow of ionic mixture with the flow of buffering substance and for releasing at the outlet a flow of buffered ionic mixture;
- the dosing device for the buffering substance is configured for receiving at the inlet a flow of buffering substance or a flow of hydroxide and for releasing at the outlet the predetermined flow of buffering substance to feed the apparatus for pH correction and the flow of alkaline substance to feed the absorber/precipitator;
- the absorber/precipitator is configured for receiving at the inlet the flow of alkaline substance released by the dosing device for the buffering substance, a flow of atmospheric air, a flow of basic solution and for releasing a flow of lean atmospheric air and a flow of PCC suspension to feed the separator;
- the separator is configured for receiving at the inlet the flow of PCC suspension and for releasing at the outlet at least a flow of PCC available to the PCC dosing device and the flow of basic solution;
- the PCC dosing device is configured for receiving at the inlet the flow of PCC and for releasing:
- a flow of dosed PCC available to feed the contactor;
- the flow of excess PCC available for any use;
- and wherein the basic solution is an aqueous solution comprising one or more of:
- NaOH, Na2CO3, KOH, and K2CO3.
15 more elements
A method to improve the efficiency of CO2 capture and storage using precipitated calcium carbonate, the method comprising steps of:
- providing an electric calciner;
- feeding to the electric calciner a flow of electric energy and a flow of carbonate to obtain the calcination of the flow of carbonate according to the reaction:
- CaCO3(s)→CaO(s)+CO2(g);
- releasing at the outlet from the electric calciner a flow of carbonic gas and a flow of oxide;
- providing a contactor;
- conveying the flow of carbonic gas to the contactor;
- providing a dosing device for the buffering substance;
- conveying the flow of oxide or a flow of hydroxide to the dosing device for the buffering substance;
- from the dosing device for the buffering substance obtaining a flow of buffering substance and a flow of alkaline substance;
- feeding to the contactor the flow of carbonic gas produced by the electric calciner, a predetermined flow of water and a flow of dosed PCC to obtain a flow of ionic mixture via reactions:
- CO2(aq)+H2O(l)H2CO3(aq)H(aq)++HCO3(aq)−
- e
- CaCO3(s)+CO2(aq)+H2O(l)→Ca(HCO3)2(aq)
- releasing at the outlet from the contactor the flow of ionic mixture;
- conveying the flow of ionic mixture;
- conveying the flow of buffering substance;
- providing an apparatus for pH correction;
- feeding the apparatus for pH correction with the flow of ionic mixture and with the predetermined flow of buffering substance;
- releasing at the outlet of the apparatus for pH correction a flow of buffered ionic mixture;
- providing an absorber/precipitator;
- feeding the flow of alkaline substance to the absorber/precipitator;
- feeding a flow of atmospheric air to the absorber/precipitator so that the reaction of the CO2 present in it takes place with the flow of alkaline substance) following the reactions:
- 2NaOH(aq)+CO2(aq)→Na2CO3(aq)+H2O(l)
- Ca(OH)2(aq)+Na2CO3(aq)→CaCO3(s)+NaOH(aq);
- or the reactions:
- 2KOH(aq)+CO2(aq)→K2CO3(aq)+H2O(l)
- Ca(OH)2(aq)+K2CO3(aq)→CaCO3(s)+KOH(aq);
- releasing at the outlet from the absorber/precipitator a flow of PCC suspension and a flow of lean atmospheric air;
- providing a separator;
- feeding the flow of PCC suspension to the separator so that a flow of PCC is separated from a flow of basic solution;
- recirculating the flow of basic solution released by the separator to the absorber/precipitator;
- providing a PCC dosing device;
- feeding the flow of PCC to the PCC dosing device;
- releasing at the outlet from the PCC dosing device the predetermined flow of dosed PCC and a predetermined flow of excess PCC;
- feeding the predetermined flow of dosed PCC to the contactor so that the reaction takes place:
- CaCO3+CO2+H2O→Ca(HCO3)2;
- and making available the predetermined flow of excess PCC.
34 more elements
Dependencies are inferred from the claim text.