Integrated Electrochemical Process for Oxalic Acid Production from CO2
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Solution Overview
Problem
Current methods for converting carbon dioxide into economically valuable materials like oxalic acid are inefficient and do not effectively utilize renewable energy sources, failing to mitigate carbon dioxide emissions effectively.
Innovation Solution
A method involving an electrochemical cell that reduces carbon dioxide to carbon monoxide, which is then converted to alkali metal oxalate through a thermal reactor, followed by an electrochemical acidification process to produce oxalic acid, utilizing renewable energy and recycling alkali metal hydroxide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional electrochemical methods are used to convert carbon dioxide, then carbon dioxide conversion occurs, but the process efficiency is low and renewable energy utilization is insufficient
Solution Approach 1:
The patent divides the carbon dioxide conversion process into two distinct electrochemical stages: first reducing CO2 to formate/CO in a basic electrolyte, then converting these intermediates to oxalic acid in an acidic electrolyte. This segmentation allows optimization of each stage for renewable energy input and improves overall conversion efficiency by preventing competing reactions that occur in single-stage systems.
Solution Approach 2:
The patent changes the pH parameter between stages - using basic conditions (high pH) for the first reduction stage to favor formate formation, then switching to acidic conditions (low pH) for the second stage to promote oxalate formation from formate/CO. This parameter change optimizes reaction pathways at each stage and enhances overall productivity while efficiently utilizing renewable energy input.
2Productivity
If single-stage electrochemical reduction is used, then process simplicity is maintained, but product yield and process efficiency are insufficient
Solution Approach 1:
The patent implements a two-electrolyzer system where the first electrolyzer operates in basic conditions to produce formate and CO from CO2, and the second electrolyzer operates in acidic conditions to convert these intermediates to oxalic acid. This segmentation increases oxalic acid yield by optimizing each stage for its specific chemical requirements, while the modular design keeps individual units relatively simple.
Solution Approach 2:
The patent creates a continuous process where the output of the first electrolyzer (formate and CO) directly feeds into the second electrolyzer without interruption. This continuous action maintains high productivity by eliminating idle time between stages, and the automated flow management keeps operational complexity manageable despite the multi-stage nature of the process.
3Object-generated harmful factors
If carbon dioxide is converted using traditional methods, then some chemical products are obtained, but emissions mitigation and renewable energy storage are not achieved
Solution Approach 1:
The patent directly converts harmful CO2 emissions into valuable oxalic acid product through electrochemical reduction. By using renewable energy to drive this conversion, the process transforms a harmful greenhouse gas into an economically valuable chemical, simultaneously achieving emissions mitigation and renewable energy utilization. The captured carbon is stored in chemical form in the oxalic acid product.
Solution Approach 2:
The patent uses the electrical energy from renewable sources directly to drive the electrochemical reduction reactions without requiring intermediate conversion steps. The system serves itself by using clean energy to convert CO2 into a useful product, creating a self-sustaining cycle where renewable energy is stored chemically in the form of oxalic acid that can be later utilized.
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 efficiently converts carbon dioxide into oxalic acid, reducing emissions while utilizing renewable energy, and allows for the recycling of alkali metal hydroxide, enhancing the overall process efficiency and sustainability.
Implementation Method 1
applying an electrical potential between the anode and cathode sufficient to reduce the carbon dioxide to at least one reduction product
Implementation Method 2
converting the at least one reduction product and the alkali metal hydroxide to an alkali metal oxalate via a thermal reactor
Implementation Method 3
converting the alkali metal oxalate to oxalic acid at the electrochemical acidification electrolyzer
Data Source
AI summary
The present disclosure is a method and system for production of carboxylic based chemicals, including carboxylic acids and salts. A method for producing at oxalic acid may include receiving an anolyte feed at an anolyte region of an electrochemical cell including an anode and receiving a catholyte feed including carbon dioxide and an alkali metal hydroxide at a catholyte region of the electrochemical cell including a cathode. Method may include applying an electrical potential between the anode and cathode sufficient to reduce the carbon dioxide to at least one reduction product and converting the at least one reduction product and the alkali metal hydroxide to an alkali metal oxalate via a thermal reactor. The method may further include receiving the alkali metal oxalate at an electrochemical acidification electrolyzer and converting the alkali metal oxalate to oxalic acid at the electrochemical acidification electrolyzer.