Fuel synthesis from an aqueous solution

• US 9,914,683 B2
• Filed: 05/26/2016
• Issued: 03/13/2018
• Est. Priority Date: 05/26/2016
• Status: Active Grant

• Current Assignee: X Development LLC (Alphabet Inc.)
• Original Assignee: X Development LLC (Alphabet Inc.)
• Inventors: Eisaman, Matthew D.
• Primary Examiner(s): PARSA, JAFAR F
• Application Number:
  US15/165,357
• Publication Number:
  US 20170342004A1
• Time in Patent Office: 656 Days
• CPC Class Codes: C01B 3/06 by reaction of inorganic compounds containing electro-positively bound hydrogen, e.g. water, acids, bases, ammonia, with inorganic reducing agents by electrolysis of water C25B1/04
• CPC Class Codes: C01B 32/50 Carbon dioxide
• CPC Class Codes: C07C 29/1518 one step being the formation of initial mixture of carbon oxides and hydrogen for synthesis
• CPC Class Codes: C07C 29/152 characterised by the reactor used
• CPC Class Codes: C07C 31/04 Methanol
• CPC Class Codes: C07C 41/09 by dehydration of compounds containing hydroxy groups
• CPC Class Codes: C07C 43/043 Dimethyl ether
• CPC Class Codes: C10G 2/30 from carbon monoxide with hydrogen
• CPC Class Codes: C10G 2/50 from carbon dioxide with hydrogen
• CPC Class Codes: C10L 1/02 essentially based on components consisting of carbon, hydrogen, and oxygen only
• CPC Class Codes: C10L 1/04 essentially based on blends of hydrocarbons
• CPC Class Codes: C10L 2290/38 Applying an electric field or inclusion of electrodes in the apparatus
• CPC Class Codes: C10L 2290/42 Fischer-Tropsch steps
• CPC Class Codes: C10L 2290/544 Extraction for separating fractions, components or impurities during preparation or upgrading of a fuel
• CPC Class Codes: C25B 1/04 by electrolysis of water
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

A method of synthesizing fuel from an aqueous solution includes pumping the aqueous solution, containing dissolved inorganic carbon, from a body of water into a carbon extraction unit. The method further includes extracting the dissolved inorganic carbon from the aqueous solution to create CO₂ by changing a pH of the aqueous solution in the carbon extraction unit. The CO₂ derived in the carbon extraction unit is received by a fuel synthesis unit, and the CO₂ is converted into fuel including at least one of a hydrocarbon, an ether, or an alcohol using the fuel synthesis unit.

Claims

1. A method of synthesizing fuel from an aqueous solution, comprising:

pumping the aqueous solution containing dissolved inorganic carbon from a body of water into a carbon extraction unit;

extracting the dissolved inorganic carbon from the aqueous solution to create CO₂ by changing a pH of the aqueous solution in the carbon extraction unit using an electrodialysis unit coupled to the carbon extraction unit, wherein in response to receiving the aqueous solution with a brine solution compartment disposed in the electrodialysis unit, the electrodialysis unit outputs at least one of aqueous NaOH or aqueous HCl to the carbon extraction unit;

receiving the CO₂ from the carbon extraction unit with a fuel synthesis unit coupled to the carbon extraction unit; and

converting the CO₂ into the fuel including at least one of a hydrocarbon, an alcohol, or an ether using the fuel synthesis unit.

2. The method of claim 1, wherein converting the CO₂ into the fuel includes reacting the CO₂ with hydrogen to produce the alcohol, and wherein the alcohol includes methanol.

3. The method of claim 2, further comprising decomposing water into the hydrogen and oxygen, in a hydrogen production unit included in the fuel synthesis unit and coupled to receive the aqueous solution, using at least one of alkaline electrolysis, polymer electrolyte membrane electrolysis, or solid oxide electrolysis.

4. The method of claim 2, wherein reacting the CO₂ with the hydrogen includes decomposing water in the aqueous solution into the hydrogen and oxygen, and reacting the hydrogen and the CO₂ in the presence of a catalyst to produce the methanol.

5. The method of claim 2, further comprising at least one of dehydrating the methanol to produce dimethyl ether, or dehydrating the methanol to produce the dimethyl ether and dehydrating the dimethyl ether to produce the hydrocarbon.

6. The method of claim 2, wherein reacting the CO₂ with the hydrogen includes:

reacting gaseous water and the CO₂ to produce CO the hydrogen, and O₂; and

reacting the CO and the hydrogen in the presence of a catalyst to produce the methanol.

7. The method of claim 1, wherein converting the CO₂ into the fuel includes:

reacting gaseous water and the CO₂ to produce CO, hydrogen, and O₂; and

using the CO and the hydrogen to perform a Fisher-Tropsch reaction to produce the hydrocarbon.

8. The method of claim 7;

wherein reacting the gaseous water and the CO₂ includes feeding the gaseous water and the CO₂ into a solid oxide electrolysis cell.

9. The method of claim 1, wherein extracting the dissolved inorganic carbon includes:

increasing the pH of the aqueous solution to precipitate salts containing carbon, wherein the aqueous solution includes seawater; and

applying acid to the salts to evolve CO₂ gas.

10. The method of claim 9, wherein increasing the pH includes adding aqueous NaOH to the aqueous solution, and wherein applying the acid to the salts includes applying the aqueous HCl to the salts.

11. The method of claim 1, wherein extracting the dissolved inorganic carbon includes decreasing the pH of the aqueous solution to remove CO₂ gas from the aqueous solution, wherein the aqueous solution includes seawater.

12. The method of claim 1, further comprising filtering the aqueous solution, with a treatment unit coupled to the electrodialysis unit to remove ions and organic matter from the water.

13. The method of claim 1, wherein the electrodialysis unit is coupled to perform operations comprising:

receiving the aqueous solution with the brine solution compartment disposed in the electrodialysis unit;

applying a voltage across electrodes in the electrodialysis unit;

outputting the aqueous solution from the brine solution compartment with a lower salt concentration in response to the voltage applied across the electrodes;

receiving the aqueous HCl with an acidified solution compartment disposed in the electrodialysis unit;

applying the voltage across the electrodes in the electrodialysis unit; and

outputting the aqueous HCl, with a higher HCl concentration, from the acidified solution compartment, wherein chlorine ions in the brine solution compartment traveled to the acidified solution compartment in response to the voltage cross the electrodes.

14. The method of claim 13, wherein the electrodialysis unit is coupled to perform operations further comprising:

receiving the aqueous NaOH with a basified solution compartment disposed in the electrodialysis unit;

applying the voltage across the electrodes in the electrodialysis unit; and

outputting the aqueous NaOH from the basified solution compartment with a higher NaOH concentration in response to the voltage applied across the electrodes.

15. The method of claim 14, wherein in response to the voltage, the chlorine ions flow through an anion exchange membrane disposed between the brine solution compartment and the acidified solution compartment, and wherein in response to the voltage, hydrogen ions and hydroxyl ions flow through a bipolar membrane disposed between the acidified solution compartment and the basified solution compartment.

16. The method of claim 15, wherein applying the voltage across the electrodes in the electrodialysis unit includes collecting sodium ions at a negatively charged terminal, and wherein the brine solution compartment, the acidified solution compartment, and the basified solution compartment are included in a first cell in a plurality of cells in the electrodialysis unit.

17. The method of claim 1, further comprising neutralizing the aqueous solution, in a pH and alkalinity adjustment unit coupled to the electrodialysis unit, with the aqueous NaOH or the aqueous HCl, after extracting the dissolved inorganic carbon from the aqueous solution.

18. The method of claim 3, wherein the hydrogen production unit and the carbon extraction unit are coupled to a CO₂ and H₂ reaction unit included in the fuel synthesis unit.

19. The method of claim 18, further comprising desalinating at least part of the aqueous solution to produce the water using a filter and desalination unit coupled to the hydrogen production unit.

20. The method of claim 18, wherein converting the CO₂ into the fuel occurs on a ship.