CO2 Mineralization via Chelating Agent pH Swing
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Solution Overview
Problem
Existing carbon dioxide fixation methods, such as the pH-swing process, require large amounts of chemicals for pH adjustment, increasing material costs, and high-temperature hydrothermal alteration of rocks raises facility costs, making them inefficient for large-scale industrial carbon dioxide mineralization.
Innovation Solution
A carbon dioxide fixation method involving an alkaline aqueous solution with a chelating agent to separate metal ions, followed by carbonate ion generation and reaction to form a carbonate mineral, with pH adjustment using injected CO2, allowing for repeated cycles without chemical reuse, reducing material and facility costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pH-swing method is used for carbon dioxide fixation, then carbonate mineral can be formed, but material costs increase due to large amounts of chemicals required for pH adjustment
Solution Approach 1:
The system uses the produced carbonate mineral and excess carbonate ions to naturally lower the pH back to initial levels, eliminating the need for additional acid chemicals. The process serves itself by using its own products for pH regulation.
Solution Approach 2:
Instead of discarding the alkaline aqueous solution after one use, the system recycles it by adding new raw materials and repeating the separation and mineral formation steps, continuously recovering and reusing the chelating agent and carbonate ions.
2Productivity
If high-temperature hydrothermal alteration is used for carbon dioxide mineralization, then dissolution rate of olivine increases, but facility costs increase
Solution Approach 1:
The invention changes the key parameter from temperature to pH and chelating agent concentration. By using alkaline conditions with chelating agents at moderate temperatures, the system achieves high dissolution rates without the facility costs associated with high-temperature equipment.
Solution Approach 2:
The invention replaces thermal energy input (high-temperature heating systems) with chemical energy input (chelating agents and alkaline conditions), substituting a mechanical/thermal system with a chemical system that achieves the same dissolution effect at lower temperatures.
3Reliability
If the pH-swing method is used, then metal ions can be carbonated to precipitate carbonate mineral, but material costs increase due to repeated addition of alkali
Solution Approach 1:
The system uses the produced carbonate mineral and excess carbonate ions to naturally lower the pH back to initial levels, eliminating the need for additional acid chemicals. The process serves itself by using its own products for pH regulation.
Solution Approach 2:
Instead of discarding the alkaline aqueous solution after one use, the system recycles it by adding new raw materials and repeating the separation and mineral formation steps, continuously recovering and reusing the chelating agent and carbonate ions.
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 fixes carbon dioxide under alkaline conditions without the need for pH adjustment chemicals, reuses the chelating agent, and operates at lower temperatures, significantly reducing material and facility costs while continuously capturing CO2 as a carbonate mineral.
Implementation Method 1
reacting the metal element with the chelating agent in the aqueous solution to separate the metal element from the raw material as metal ions
Implementation Method 2
adding a compound that can generate carbonate ions in the aqueous solution to form a carbonate mineral by reacting the carbonate ions generated from the compound with the metal ions
Implementation Method 3
injecting carbon dioxide gas into the aqueous solution after the mineral formation step to lower a pH to the pH of the aqueous solution formed in the aqueous solution formation step or a value near that
Data Source
AI summary
A carbon dioxide fixation method, recovery method, fixation device and environmentally friendly industrial facility which can reduce material and facility costs. In aqueous solution formation, alkaline solution including: raw material including metal element which can combine with carbonate ions to form carbonate mineral; and chelating agent is formed. In separation, element is reacted with agent in solution to separate element from raw material as metal ions. In mineral formation, compound which can generate carbonate ions is added into solution to react ions generated from compound with metal ions to form carbonate mineral. In pH lowering, carbon dioxide gas is injected into solution to lower pH thereof to a value of or near pH of solution formed in the solution formation. In repetition, new raw material is added into solution to perform separation to pH lowering steps.