Electrolytic Cell Ammonia Synthesis from Nitrogen and Water Vapor
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Solution Overview
Problem
Current ammonia production methods, such as the Haber-Bosch process, require high temperatures and pressures, leading to inefficient energy use and significant thermodynamic losses, and lack scalable electrolytic cell solutions for producing ammonia from nitrogen and water.
Innovation Solution
A method involving an electrolytic cell that separates ammonia from nitrogen, water, and other components, using nitrogen and water as starting materials, with optional argon separation and recycling of nitrogen and water to improve efficiency and yield, and incorporating a refrigeration system for ammonia purification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the Haber-Bosch process is used for ammonia production, then ammonia can be produced at large scale, but high temperatures and pressures are required leading to high energy consumption and thermodynamic losses
Solution Approach 1:
The patent replaces the mechanical/thermal system of Haber-Bosch (high temperature and pressure) with an electrochemical system using electrolysis cells. The electrolysis process uses electrical energy to drive the ammonia synthesis reaction at lower temperatures, substituting thermal-mechanical activation with electrochemical activation. This is achieved through electrochemical cells that facilitate nitrogen reduction and hydrogen evolution reactions at significantly lower energy inputs than conventional thermal processes.
Solution Approach 2:
The patent fundamentally changes the operating parameters from high temperature (400-500°C) and high pressure (100-450 bar) in Haber-Bosch to near-ambient temperature and pressure conditions in electrolysis. By changing the activation method from thermal to electrochemical, the process operates under milder conditions while maintaining scalability through modular electrolysis cell stacks that can be configured for large-scale production.
2Productivity
If high temperatures and pressures are used in ammonia synthesis, then the reaction proceeds at acceptable rates, but the reactors become technically sophisticated and sensitive to operating condition changes
Solution Approach 1:
The patent replaces complex high-pressure reactors with simpler electrolysis cells that operate at atmospheric or near-atmospheric pressures. The electrochemical reaction occurs at electrode surfaces where nitrogen and water are converted to ammonia through electrochemical reactions, eliminating the need for sophisticated high-pressure containment and control systems required by Haber-Bosch reactors.
Solution Approach 2:
The patent divides the ammonia production system into modular electrolysis cells that can be stacked and scaled independently. Each cell is a simple, robust unit with electrodes and electrolyte, avoiding the single complex reactor design of Haber-Bosch. This segmentation allows for easier maintenance, reduced sensitivity to operating condition changes, and flexible scaling by adding or removing cell modules.
3Quantity of substance
If conventional hydrogen production is used in electrolytic ammonia synthesis, then hydrogen is available for the reaction, but the process inherits the disadvantages of conventional synthesis gas production including carbon dioxide emissions
Solution Approach 1:
The patent extracts the hydrogen production step from the conventional natural gas reforming process and replaces it with direct water electrolysis. By taking out the carbon-intensive hydrogen production环节 and substituting it with electrochemical water splitting, the process eliminates carbon dioxide emissions while ensuring adequate hydrogen supply for ammonia synthesis through the electrolytic generation of hydrogen from water.
Solution Approach 2:
The patent makes the system self-sufficient by producing both hydrogen and the necessary electrochemical environment within the electrolysis cell itself. Water is electrolyzed to provide hydrogen in-situ for ammonia synthesis, eliminating the need for external hydrogen production facilities and their associated carbon emissions. The system serves its own hydrogen needs through integrated water electrolysis.
4Use of energy by moving object
If ammonia is produced electrolytically from nitrogen and water, then energy consumption is reduced, but separation of ammonia from unreacted nitrogen and water requires additional processing steps
Solution Approach 1:
The patent utilizes phase transition differences to simplify separation. Ammonia has a significantly higher boiling point than nitrogen and water vapor, allowing the product stream to be separated by condensation. The ammonia condenses at higher temperatures while nitrogen and excess water vapor remain gaseous, enabling simple thermal separation without complex distillation columns or advanced separation technologies.
Solution Approach 2:
The patent converts the challenge of having unreacted nitrogen and water in the product stream into a benefit by using the high concentration of ammonia in the condensate. The condensation process naturally concentrates ammonia while leaving most nitrogen and water vapor in the gas phase, turning the separation challenge into a simple thermal process that leverages the physical properties of the components rather than requiring complex separation equipment.
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 enables efficient large-scale ammonia production with reduced energy consumption and minimized losses, achieving high-purity ammonia through a multi-step separation and recycling process.
Implementation Method 1
electrolysis using at least one electrolysis cell, nitrogen being fed into the electrolysis cell as the first starting material and water or steam being used as the second starting material for the electrolysis
Implementation Method 2
a refrigeration system for purifying the ammonia
Data Source
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AI summary
The present invention relates to a process for preparing ammonia by electrolysis using at least one electrolysis cell (14), wherein a) nitrogen is fed into the electrolysis cell as the first reactant and b) water in the form of water vapour is used as the second reactant for the electrolysis. There is no existing process to date for the industrial scale preparation of ammonia based on an electrolysis cell in which water and nitrogen are used as starting materials. Therefore, in the context of the present invention, a concept for a process and a plant has been developed, in which this specific electrolysis cell is used. According to the invention, at least one step c) downstream of the electrolysis is provided, in which a separation of other components from the ammonia is effected, especially an at least partial separation of one or more components from the group comprising nitrogen, water, argon and hydrogen. The recovery of the reactants is upstream of the ammonia electrolysis. Preferably, according to the invention, the nitrogen used as the first reactant as per a) has been obtained in an air fractionation plant (10) beforehand.