CO2 Electrolysis pH Gradient Suppresses Hydrogen
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Solution Overview
Problem
Current carbon dioxide treatment technologies face challenges in achieving high energy efficiency and reducing carbon dioxide loss during recovery and reduction processes, particularly due to side reactions like hydrogen generation during water electrolysis.
Innovation Solution
A carbon dioxide treatment apparatus and method that includes a recovery device for concentrating carbon dioxide, an electrochemical reaction device with a pH adjuster to optimize electrolytic solutions' pH for reduced hydrogen generation, and a power storage device to efficiently supply energy, all working together to enhance energy efficiency and minimize carbon dioxide loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carbon dioxide is electrochemically reduced using conventional electrolysis, then carbon dioxide can be converted to valuable resources, but hydrogen is generated by water electrolysis as a side reaction causing energy loss
Solution Approach 1:
The invention changes the pH parameter of the electrolytic solution to create a pH gradient between the anode and cathode compartments. By maintaining the cathode side at high pH (using strong alkaline aqueous solution) and the anode side at lower pH, the invention suppresses hydrogen generation at the cathode while promoting carbon dioxide reduction, thus resolving the energy loss issue without sacrificing productivity
2Reliability
If carbon dioxide recovery and reduction processes are implemented, then carbon neutrality can be achieved, but economic efficiency remains the biggest issue due to energy consumption
Solution Approach 1:
By optimizing the pH parameter throughout the system - using strong alkaline aqueous solution at the cathode, maintaining appropriate pH in the absorption tower, and controlling pH in the concentration unit - the invention significantly improves energy efficiency while maintaining reliable carbon dioxide conversion, thus making carbon neutrality economically viable
3Ease of operation
If conventional electrolysis is used without pH control, then the process is simpler to operate, but hydrogen generation cannot be suppressed when catalysts deteriorate
Solution Approach 1:
The invention establishes a pH gradient as a fundamental operating parameter - maintaining high pH at the cathode and lower pH at the anode through controlled addition of strong alkaline aqueous solution. This parameter change creates an environment that inherently suppresses hydrogen generation even when catalysts deteriorate, while remaining relatively simple to implement through automated pH control systems
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
The apparatus and method significantly improve energy efficiency in carbon dioxide recovery and reduction, reducing hydrogen generation and overall carbon dioxide loss, thereby enhancing the economic viability of achieving carbon neutrality.
Implementation Method 1
an anode side electrolytic solution composed of a strong alkaline aqueous solution and carbon dioxide gas are brought into contact with each other so that the carbon dioxide is dissolved and absorbed in the anode side electrolytic solution
Implementation Method 2
the carbon dioxide gas is reduced at the cathode
Implementation Method 3
an anion exchange membrane provided between the anode and the cathode
Data Source
AI summary
A carbon dioxide treatment apparatus, a carbon dioxide treatment method, and a method for producing a carbon compound that have high energy efficiency in recovery and reduction of carbon dioxide and are highly effective in reducing loss of carbon dioxide. The carbon dioxide treatment apparatus (100) includes a recovery device (1) configured to recover carbon dioxide, an electrochemical reaction device (2) configured to electrochemically reduce carbon dioxide, and a pH adjuster (52), wherein pH of a cathode side electrolytic solution is higher than that of an anode side electrolytic solution, carbon dioxide gas is supplied from a concentration part 11 to a gas flow path on a side of a cathode (21) opposite to an anode (22), and the carbon dioxide gas is reduced at the cathode (21).