Roll-Type Electrochemical Ammonia Recovery Device
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electrochemical ammonia recovery technologies require additional acid solutions or acid-producing units, increasing construction and operation costs, and cannot directly utilize H+ generated by electrode reactions for ammonia recycling.
Innovation Solution
A roll-type device with a two-chamber structure, utilizing a hydrophobic gas membrane and anion-exchange membrane, where the cathode liquid flows independently to increase pH and convert NH4+ to NH3, which then diffuses through the membrane and is captured by H+ generated at the anode, allowing ammonia recovery without additional chemical agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If additional acid solutions or acid-producing units are used in electrochemical ammonia recovery, then ammonia recovery efficiency is improved, but construction and operation costs increase
Solution Approach 1:
The system uses self-service by generating H+ ions in situ at the anode through electrochemical oxidation of water, eliminating the need for external acid solutions or acid-producing units. The anode reaction 2H2O → O2 + 4H+ + 4e- provides the necessary protons for ammonia recovery, making the system self-sufficient and reducing operational costs.
Solution Approach 2:
The invention merges the acid generation function with the electrochemical ammonia recovery process by integrating the H+ generation at the anode directly into the ammonia recovery chamber. This combines what were previously separate functions (acid production and ammonia recovery) into a single integrated system, reducing device complexity and operational costs.
2Quantity of substance
If traditional electrochemical ammonia recovery methods are used, then ammonia can be recovered, but additional chemical agents and acid-producing units are required
Solution Approach 1:
The system eliminates the need for external chemical agents by generating H+ ions in situ at the anode through electrochemical oxidation. The anode reaction 2H2O → O2 + 4H+ + 4e- provides the necessary protons for converting NH3 to NH4+, making the system self-sufficient without requiring external acid addition.
Solution Approach 2:
The invention extracts and eliminates the need for external acid-producing units by integrating the H+ generation function directly into the electrochemical cell's anode. This removes the separate acid production step and combines it with the ammonia recovery process, simplifying the overall system.
3Productivity
If electrochemical reactions are used to increase pH and convert NH4+ to NH3, then ammonia can be released for recovery, but energy consumption increases
Solution Approach 1:
The system optimizes energy consumption by carefully controlling the pH parameter in the cathode chamber to maintain conditions favorable for NH3 generation without excessive energy input. The pH is adjusted to just above the pKa of NH4+ (9.25) to ensure sufficient NH3 release while minimizing energy waste.
Solution Approach 2:
The electrochemical process operates continuously with steady current application, maintaining constant pH conditions in the cathode for continuous NH3 generation and simultaneous H+ generation at the anode for immediate NH3 capture, ensuring continuous useful action without energy-wasting interruptions.
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 approach significantly reduces costs, improves efficiency, and enables high current density ammonia recovery, achieving over 99% removal and 98% recovery rates without additional chemical agents or acid-producing units.
Implementation Method 1
NH3 escapes from a solution, and the escaped NH3 gas diffuses through an absorption tower or a hydrophobic gas membrane to an absorption chamber/tank
Implementation Method 2
anions (such as Cl− and SO42−) in the cathode liquid enter the anode liquid flow chamber through the AEM
Implementation Method 3
A large amount of OH− is generated due to an electrochemical reaction at a cathode and reacts with the migrated NH4+ to produce NH3
Implementation Method 4
Generating a large amount of H+ through an electrochemical reaction at an anode, absorbing the NH3 diffusing from the cathode liquid flow chamber to the anode liquid flow chamber
Data Source
AI summary
A roll-type device for electrochemical recovery of ammonia is provided, including: a central tube and a tubular shell, where a hydrophobic gas membrane and an anion-exchange membrane (AEM) are sequentially wound around the central tube; a first porous flexible electrode and a first guide liner are sequentially wound at an inner side of the hydrophobic gas membrane, and a second porous flexible electrode and a second guide liner are sequentially wound at an inner side of the AEM; an inner side wall of the hydrophobic gas membrane, an outer wall of the central tube, an outer side wall of the AEM, and the tubular shell enclose a closed first electrode liquid flow chamber; and an inner side wall of the AEM, an outer wall of the central tube, an outer side wall of the hydrophobic gas membrane, and the tubular shell enclose a closed second electrode liquid flow chamber.