Direct gas capture systems and methods of use thereof

Patent metadata

Field	Value
Publication number	US-2020108346-A1
Application number	US-201916593197-A
Country	US
Kind code	A1
Filing date	Oct 4, 2019
Priority date	Oct 5, 2018
Publication date	Apr 9, 2020
Grant date	—

Abstract

The present disclosure provides systems and methods that combine direct capture of one or more moieties from a gaseous mixture with one or both of calcium oxide production and power production. The systems and methods can utilize combinations of a capture unit, a regeneration unit, a calcination unit, a slaking unit, a heat exchange unit, a separation unit, and a power production unit. The present disclosure provides the ability to remove carbon dioxide and other moieties from air or other gaseous mixtures in a truly carbon negative manner by utilizing electricity from a power production unit that is operated in a carbon neutral or carbon negative manner and simultaneously provide useful products, such as calcium oxide and calcium hydroxide.

First claim

1 . A system for direct capture of carbon dioxide from air with simultaneous power production and generation of one or both of calcium oxide and calcium hydroxide, the system comprising:
a capture unit configured for receiving an alkali solvent and air and providing an intermediate product incorporating carbon dioxide removed from the air; a regeneration unit configured for receiving the intermediate product incorporating the carbon dioxide and a stream of calcium hydroxide and providing a stream of the alkali solvent and a stream comprising calcium carbonate; a calcination unit configured for receiving the stream comprising calcium carbonate and heating the calcium carbonate to form calcium oxide and provide a heated gas stream; a slaking unit configured for receiving a portion of the calcium oxide and water and providing the stream of calcium hydroxide that is received by the regeneration unit; a heat recovery unit configured to receive the heated gas stream from the calcination unit and provide a cooled gas stream; and a power production unit configured to receive heat provided from one or more of the calcination unit, the heat recovery unit, and the slaking unit.

2 . The system of claim 1 , wherein the power production unit is a closed loop power production unit.

3 . The system of claim 1 , wherein the power production unit is a semi-closed loop power production unit.

4 . The system of claim 3 , wherein the semi-closed loop power production unit is configured for repeated compression and expansion of a carbon dioxide working fluid.

5 . The system of claim 1 , wherein the system further comprises a separator configured to receive the cooled gas stream from the heat exchange unit and provide a stream of substantially pure carbon dioxide.

6 . A method for direct capture of carbon dioxide from air with simultaneous power production and generation of one or both of calcium oxide and calcium hydroxide, the method comprising:
contacting air with an alkali solvent in a contacting unit under conditions effective to react the alkali solvent with carbon dioxide in the air and form an intermediate product incorporating the carbon dioxide removed from the air; regenerating the alkali solvent in a regenerating unit by reacting the intermediate product incorporating the carbon dioxide with calcium hydroxide to form a regenerated alkali solvent and form calcium carbonate; heating the calcium carbonate in a calcination unit to form calcium oxide and provide a heated gas stream; reacting a portion of the calcium oxide with water to form calcium hydroxide, at least a portion which is passed to the regenerating unit; withdrawing heat from the heated gas stream to form a cooled gas stream; and using at least a portion of the heat withdrawn from the heated gas stream or a heated solids stream to heat one or more streams in a power production unit.

7 . The method of claim 6 , wherein the alkali solvent comprises one or both of potassium hydroxide and sodium hydroxide.

8 . The method of claim 7 , wherein the intermediate product comprises one or both of potassium carbonate and sodium carbonate.

9 . The method of claim 6 , comprising recycling at least a portion of the regenerated alkali solvent back to the contacting unit.

10 . The method of claim 6 , wherein heating the calcium carbonate in the calcination unit comprises injecting a fuel and an oxidant into the calcination unit under conditions effective to at least partially combust the fuel to produce heat.

11 . The method of claim 6 , further comprising injecting a stream of makeup calcium carbonate into the calcination unit.

12 . The method of claim 6 , further comprising exporting a portion of the calcium oxide formed in the calcination unit as a calcium oxide product stream.

13 . The method of claim 6 , wherein the calcination unit is operated at a temperature of 700° C. to about 1300° C.

14 . The method of claim 6 , further comprising passing the heated gas stream or the cooled gas stream to a separation unit and forming a substantially pure stream of carbon dioxide.

15 . The method of claim 14 , further comprising compressing at least a portion of the substantially pure stream of carbon dioxide to a pressure of about 20 bar to about 200 bar.

16 . The method of claim 6 , further comprising cooling at least a portion of the formed calcium oxide prior to reacting a portion of the calcium oxide with water to form calcium hydroxide.

17 . The method of claim 6 , wherein the slaking unit is operated in a temperature range of about 125° C. to about 600° C.

18 . The method of claim 6 , wherein withdrawing heat from the heated gas stream to form a cooled gas stream comprises passing the heated gas stream through a heat exchanger where heat is withdrawn therefrom.

19 . The method of claim 18 , wherein at least a portion of the heat that is withdrawn from the heated gas stream in the heat exchanger is used for pre-heating the calcium carbonate entering the calcination unit.

20 . The method of claim 19 , wherein the calcium carbonate is heated up to a temperature of about 400° C. to about 800° C.

21 . The method of claim 18 , wherein using at least a portion of the heat withdrawn from the heated gas stream or the heated solids stream to heat one or more streams in the power production unit comprises using one or more exhaust streams in a gas phase or a solid phase from the slaking unit to transfer heat to one or more streams in the power production unit.

22 . The method of claim 18 , further comprising using electricity generated in the power production unit to supply at least a portion of an electrical load requirement necessary for operation of at least the contacting unit.

23 . The method of claim 6 , wherein the power production unit is a closed loop power production unit or a semi-closed loop power production unit.

24 . The method of claim 23 , wherein the power production unit is the semi-closed loop power production unit and is configured for repeated compression and expansion of a carbon dioxide working fluid.

25 . The method of claim 6 , wherein the contacting unit includes a solid state absorbent unit, and wherein the air used in the contacting unit is first passed through the solid state absorbent unit.

26 . The method of claim 6 , wherein the air used in the contacting unit is first compressed in an air separation unit prior to being passed to the contacting unit.

27 . The method of claim 26 , wherein the air separation unit is used to produce oxygen for one or both of the power production unit and the calcination unit.

28 . The method of claim 6 , wherein the power production unit includes a power production turbine, and wherein all or part of an exhaust stream from the power production turbine is used to provide heating for the calcination unit.

Assignees

• 8 Rivers Capital Llc

Inventors

• Lu Xijia
• Fetvedt Jeremy Eron
• Forrest Brock Alan
• Brown Jr Glenn William
• Rafati Mohammad
• Martin Scott Thomas

Classifications

• B01D2251/306

  of potassium · CPC title

• B01D53/02

  by adsorption, e.g. preparative gas chromatography {(solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01)} · CPC title

• B01D53/62

  Carbon oxides · CPC title

• C01B32/50

  Carbon dioxide · CPC title

• B01D2258/06

  Polluted air · CPC title