Electrochemical Seawater Acidification for CO2 Extraction
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Solution Overview
Problem
Current methods for extracting carbon dioxide from seawater are not practical for sea-based operations due to inefficiencies and high resource requirements, limiting the production of jet fuel for aircraft carriers.
Innovation Solution
An electrochemical acidification cell that exchanges sodium ions for hydrogen ions in seawater, lowering the pH to facilitate carbon dioxide extraction and producing hydrogen for hydrocarbon synthesis, using an apparatus with ion exchange compartments and cation-permeable membranes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional CO2 extraction methods are used from seawater, then carbon dioxide can be obtained for fuel synthesis, but the process requires excessive water volume and resource inputs making it impractical for sea-based operations
Solution Approach 1:
The patent changes the pH parameter of seawater by introducing acid (lowering pH to 4.5 or below) to convert bicarbonate ions (HCO3-) into carbonic acid (H2CO3) which then decomposes to CO2 gas. This parameter change enables efficient CO2 extraction without requiring excessive water volumes, resolving the contradiction between CO2 extraction efficiency and operational productivity
Solution Approach 2:
The patent utilizes the phase transition of carbonic acid decomposing into CO2 gas and water. By acidifying seawater to convert dissolved bicarbonate into carbonic acid, the system triggers a chemical phase transition that releases CO2 gas for collection, achieving high extraction efficiency with reduced water requirements
2Quantity of substance
If ion exchange resin is used to acidify seawater for CO2 extraction, then CO2 can be recovered, but the volume of water required to regenerate the resin exceeds the volume of CO2 recovered
Solution Approach 1:
The patent extracts and removes the ion exchange resin regeneration step from the overall process by using direct acid addition instead. This eliminates the need to cycle large volumes of water through resin regeneration, thereby reducing water consumption below the volume of CO2 recovered while maintaining effective acidification for CO2 extraction
3Quantity of substance
If large volumes of seawater are processed to extract sufficient CO2 for jet fuel production, then fuel can be synthesized, but the operational footprint and resource requirements increase significantly
Solution Approach 1:
By changing the pH parameter through direct acid addition rather than processing large volumes of seawater through conventional methods, the system achieves sufficient CO2 availability for jet fuel synthesis with a reduced operational footprint, eliminating the need for extensive water handling infrastructure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively acidifies seawater to extract carbon dioxide and produces hydrogen, enabling the production of hydrocarbons like jet fuel, reducing operational footprint and resource needs for sea-based fuel production.
Implementation Method 1
an ion exchange (IX) compartment, a cathode electrode compartment, an anode electrode compartment and cation-permeable membranes... subjected to an ion exchange reaction to exchange H+ ions for Na+ ions to thereby acidify the seawater
Implementation Method 2
a cathode located in the cathode electrode compartment, an anode located in the anode electrode compartment and a means for application of current to each of the cathode and anode... produces hydrogen for hydrocarbon synthesis
Implementation Method 3
cation-permeable membranes, which separate the cathode and anode electrode compartments from the ion exchange compartment
Data Source
AI summary
Apparatus for seawater acidification including an ion exchange, cathode and anode electrode compartments and cation-permeable membranes that separate the electrode compartments from the ion exchange compartment. Means is provided for feeding seawater through the ion exchange compartment and for feeding a dissociable liquid media through the anode and cathode electrode compartments. A cathode is located in the cathode electrode compartment and an anode is located in the anode electrode compartment and a means for application of current to the cathode and anode is provided. A method for the acidification of seawater by subjecting the seawater to an ion exchange reaction to exchange H+ ions for Na+ ions. Carbon dioxide may be extracted from the acidified seawater. Optionally, the ion exchange reaction can be conducted under conditions which produce hydrogen as well as carbon dioxide. The carbon dioxide and hydrogen may be used to produce hydrocarbons.