Electrochemical CO2 Conversion to Oxalic Acid via Membrane Segmentation
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Solution Overview
Problem
Current methods for electrochemical conversion of CO2 to oxalate in non-aqueous media face challenges in producing oxalic acid efficiently and safely, as oxalate has limited utility and often results in toxic halogen byproducts.
Innovation Solution
A method involving an electrochemical cell with a cathode and an anode separated by an anion exchange membrane, where carbon dioxide is reduced to oxalate in one region and acidified to produce oxalic acid in another, using a hydrogen gas stream and electrical potential, without producing toxic compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electrochemical reduction of CO2 is performed in non-aqueous media to produce oxalate, then CO2 conversion is achieved, but oxalic acid cannot be efficiently produced and toxic halogen byproducts are generated
Solution Approach 1:
The electrochemical cell is divided into two separate regions by an anion exchange membrane: a cathode region for CO2 reduction to oxalate, and an anode region for oxalate acidification to oxalic acid. This spatial segmentation allows each region to perform its specific function without interference, enabling efficient oxalic acid production while avoiding toxic byproducts
Solution Approach 2:
An anion exchange membrane serves as an intermediary between the cathode and anode regions, selectively allowing anion transport while preventing direct contact between the catholyte and anolyte. This intermediary structure enables the acidification process to occur without generating toxic halogen byproducts that would result from direct mixing
2Device complexity
If oxalate is produced directly without separation, then CO2 reduction is simplified, but oxalic acid production is limited and product utility is reduced
Solution Approach 1:
The cell is segmented into functional zones that enable sequential processing: CO2 reduction in the cathode region followed by oxalate acidification in the anode region. This segmentation transforms a single-step process into a multi-stage process that produces valuable oxalic acid while maintaining reasonable structural complexity
Solution Approach 2:
The electrochemical cell design enables multiple functions within a single system: CO2 reduction, oxalate production, oxalate acidification, and oxalic acid generation. This multi-functionality increases product utility and industrial applicability without requiring multiple separate processing units
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 converts CO2 to oxalic acid, which has broader industrial applications, while avoiding toxic byproducts and enabling the production of valuable reduction products like mono-ethylene glycol, thus mitigating carbon dioxide emissions.
Implementation Method 1
the carbon dioxide is reduced to an oxalate in the first region
Implementation Method 2
the hydrogen is oxidized to hydrogen ions in the second region
Implementation Method 3
an anion exchange membrane, AEM, or separator between the first region and the second region
Data Source
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AI summary
The present disclosure is a method and system for production of oxalic acid and oxalic acid reduction products. The production of oxalic acid and oxalic acid reduction products may include the electrochemical conversion of CO2 to oxalate and oxalic acid. The method and system for production of oxalic acid and oxalic acid reduction products may further include the acidification of oxalate to oxalic acid, the purification of oxalic acid and the hydrogenation of oxalic acid to produce oxalic acid reduction products.