Reverse Electrodialysis Membrane with Integrated Channels
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Solution Overview
Problem
Existing reverse electrodialysis membranes suffer from high electrical resistance and high costs due to the use of materials and spacers, leading to low efficiency in electricity generation.
Innovation Solution
The introduction of channels within the membrane to promote laminar fluid flow, reducing internal electrical resistance and eliminating the need for spacers, which simplifies assembly and reduces friction losses, while using sulphochlorinated polyolefin materials for cost-effectiveness and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If spacers are used to separate membranes, then flow between membranes is enabled, but flow resistance increases and electrical resistance increases due to shadow effect
Solution Approach 1:
The invention extracts and eliminates the spacer component from the system. Instead of using separate spacers to maintain distance between membranes, the membranes themselves are designed with integrated channel structures that provide the necessary spacing and flow paths without requiring additional spacer elements. This removal of spacers eliminates both the hydraulic flow resistance and the electrical shadow effect that spacers cause.
Solution Approach 2:
The invention merges the spacing function and flow channel function into the membrane structure itself. The channels are formed directly in the membranes, combining what were previously separate functions (membrane separation and flow guidance) into an integrated structure. This eliminates the need for separate spacer components and reduces both hydraulic and electrical resistance.
2Productivity
If turbulent flow is created to increase limiting flow strength, then mass transfer is improved, but friction losses increase and pump power requirements increase
Solution Approach 1:
The invention changes the flow regime parameter from turbulent to laminar flow. By carefully designing the channel dimensions and maintaining appropriate flow rates, the system operates in the laminar flow regime where friction losses are significantly reduced compared to turbulent flow, while still achieving adequate mass transfer through the concentration gradient-driven ion transport in reverse electrodialysis.
3Ease of operation
If membrane distance is increased to allow flow, then flow is enabled, but internal electrical resistance increases
Solution Approach 1:
The invention transitions from a two-dimensional spacing approach to a three-dimensional channel structure. Instead of simply increasing the distance between membranes in one dimension, the system creates defined three-dimensional flow channels with optimized cross-sectional areas and paths. This allows sufficient spacing for flow while maintaining short current paths through the electrolyte, thereby minimizing electrical resistance.
4Ease of manufacture
If spacers are used to separate membranes, then assembly is simplified, but device complexity increases due to additional components
Solution Approach 1:
The invention merges multiple functions into the membrane structure itself. The membranes are manufactured with integrated channel structures that provide spacing, flow guidance, and structural support without requiring separate spacer components. This reduction in component count simplifies the overall device assembly while maintaining ease of manufacture through integrated membrane 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
This configuration enhances the efficiency of the reverse electrodialysis process by lowering pump power requirements, reducing internal resistance, and minimizing leakage, resulting in a more cost-effective and efficient electricity generation system.
Implementation Method 1
The channels are provided with dimensions such that a substantially laminar flow of the fluid results in the channels
Implementation Method 2
A voltage is here applied between an anode and a cathode, between which a number of anion and cation exchange membranes are alternately placed. Owing to the applied voltage positive ions tend to move toward the cathode and negative ions tend to move toward the anode.
Implementation Method 3
This is reverse electrodialysis. A device for performing such a reverse electrodialysis process can generate electric energy
Data Source
Figure 1
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Figure 3~6
AI summary
Membrane, cell and device suitable for reverse electrodialysis for the purpose of generating electricity, and methods therefor, the membrane comprising a number of channels arranged on at least a first side of the membrane, wherein the channels are suitable for throughfeed of a fluid, wherein the dimensions of the channels are aimed at obtaining a laminar flow of the fluid in the channels.