Electrolysis-Driven Forward Osmosis for Low-Energy Water Purification
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Solution Overview
Problem
Desalination and liquid purification processes are energy-intensive and carbon footprint-heavy, particularly for large-scale water desalination, which often relies on reverse osmosis and expensive plants, detracting from energy storage goals.
Innovation Solution
Utilize forward osmosis through a semipermeable membrane driven by electrolysis to create and maintain a concentration gradient, allowing liquid purification while producing electrolysis products like hydrogen and oxygen, which can be used for energy generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If reverse osmosis is used to desalinate saltwater, then molecularly pure water can be produced, but the process becomes energy-intensive and expensive
Solution Approach 1:
The patent inverts the conventional reverse osmosis approach by using forward osmosis. Instead of forcing water through a membrane against a concentration gradient (reverse osmosis), the system allows water to naturally flow from a low-salinity source across a semipermeable membrane into a high-salinity draw solution (forward osmosis). This inversion eliminates the need for high-pressure pumps and significantly reduces energy consumption while maintaining water purification effectiveness.
Solution Approach 2:
The patent replaces the mechanical high-pressure system of reverse osmosis with an electrochemical system. electrodes are used to generate the draw solution in-situ through electrolysis of water, creating the concentration gradient needed for forward osmosis without requiring mechanical pressure. This substitution of mechanical energy with electrochemical energy enables scalable, low-energy water purification.
2Quantity of substance
If reverse osmosis plants are used for large-scale water purification, then abundant pure water can be produced, but the infrastructure cost increases and energy consumption rises
Solution Approach 1:
The patent segments the water purification process into modular electrochemical cells, each containing a semipermeable membrane and electrodes. These modular units can be scaled by simply adding more cells in series or parallel, eliminating the need for complex centralized infrastructure. Each module independently produces pure water and can be configured to match the required production scale, making the system both scalable and infrastructure-light.
Solution Approach 2:
The draw solution serves multiple functions: it provides the concentration gradient for forward osmosis, acts as an electrolyte for electrochemical water splitting, and can be regenerated in-situ. This multi-functionality reduces the number of separate systems needed, simplifying infrastructure while maintaining large-scale production capability.
3Speed
If conventional electrolysis is used to create concentration gradients, then forward osmosis can be driven, but the process may not be sustainable without additional energy input
Solution Approach 1:
The patent merges two processes into one integrated system: forward osmosis and electrochemical water splitting. The electrolysis that creates the concentration gradient to drive forward osmosis is performed using the same water that is being purified, and the products of water splitting (hydrogen and oxygen) are valuable energy carriers. This merging eliminates the need for separate energy input systems and makes the overall process sustainable by producing energy-dense products.
Solution Approach 2:
The patent converts what would normally be a harmful or wasteful process (electrolysis consuming energy) into a beneficial outcome. By using electrolysis to create the draw solution for forward osmosis, the system simultaneously produces hydrogen and oxygen gases that can be stored and used as clean energy sources, turning energy consumption into energy production.
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
Achieves efficient liquid purification with reduced energy consumption and carbon footprint by using renewable energy sources, producing valuable electrolysis products that can be stored or used for energy generation.
Implementation Method 1
a semipermeable membrane disposed between the first volume and the second volume, wherein the semipermeable membrane is permeable to the water, wherein the semipermeable membrane is configured to exclude the at least one contaminant from the second volume
Implementation Method 2
A concentration gradient across the semipermeable membrane can be provided and maintained by electrolysis of the liquid and can drive forward osmosis of the liquid through the semipermeable membrane
Implementation Method 3
The liquid (e.g., water) containing the contaminant may flow through a semipermeable membrane (e.g., via forward osmosis) that is not permeable to the contaminant in order to remove the contaminant from the liquid
Data Source
AI summary
Systems and methods for removing a contaminant from a liquid are generally described. The liquid (e.g., water) containing the contaminant may be flowed across a semipermeable membrane (e.g., via forward osmosis) that is not permeable to the contaminant in order to remove the contaminant from the liquid. A concentration gradient across the semipermeable membrane may be provided and maintained by electrolysis of the liquid and can drive forward osmosis of the liquid through the semipermeable membrane.