Heat-Pump RED Cell for Closed-Loop Salinity Gradient Recovery
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Solution Overview
Problem
Existing salt gradient power systems, such as reverse electrodialysis (RED) batteries, face limitations due to the need for continuous sources of salt and fresh water, susceptibility to contamination, and energy-intensive regeneration of salinity differences, which restricts practical locations and efficiency.
Innovation Solution
A method and system that utilize a selectively permeable membrane to separate and mix saline solutions, transferring thermal energy to regenerate salinity gradients, capturing electrical power through salinity-gradient energy and regenerating the salinity difference using processes like salt decomposition, electrodialysis, membrane distillation, or forward osmosis, with the option to produce hydrogen through electrolysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If open-loop RED batteries are used to retrieve energy from salinity gradient, then energy generation is achieved, but the system requires continuous sources of salt and fresh water which limits practical locations
Solution Approach 1:
The invention extracts the dependence on continuous external water sources by implementing a closed-loop system with internal regeneration. The regeneration system recovers and recycles salt from the mixing zone, allowing the system to operate with minimal external inputs and adapt to various locations including areas without continuous fresh water sources.
Solution Approach 2:
The system changes the operational parameters from open-loop continuous flow to closed-loop regeneration mode. By implementing thermal regeneration processes (evaporation, freezing, heating) that alter the salinity parameters internally, the system maintains energy generation capability while becoming location-independent.
2Use of energy by moving object
If open-loop RED batteries are used, then energy generation is achieved, but the system is susceptible to contamination from minerals, microbes, or other foreign objects
Solution Approach 1:
The invention removes the system's vulnerability to contamination by closing the loop and regenerating solutions internally. The regeneration processes (thermal treatment, evaporation, freezing) effectively remove contaminants and minerals, preventing their accumulation and harmful effects while maintaining continuous energy generation.
Solution Approach 2:
The system converts potentially harmful contaminants and minerals into beneficial resources. Contaminants are concentrated during the regeneration process and can be harvested or utilized, while the regenerated clean solutions are returned to the system, turning what was previously a harm into a benefit.
3Adaptability or versatility
If closed-loop RED cells are used to avoid contamination and location limitations, then system adaptability is improved, but ongoing regeneration of salinity difference becomes energy intensive and inefficient
Solution Approach 1:
The regeneration system is designed to be self-sufficient, utilizing the salinity gradient energy produced by the RED battery itself to drive the regeneration processes. The system serves its own regeneration needs, minimizing external energy inputs and improving overall efficiency while maintaining closed-loop operation.
Solution Approach 2:
The invention merges the energy generation function with the regeneration function into an integrated system. The thermal regeneration processes are coupled with the RED battery operation, allowing heat exchange and energy recovery between the two functions, thereby reducing total energy consumption while maintaining system adaptability.
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 generation of electrical power and hydrogen from thermal energy, overcoming the limitations of continuous water sources and contamination susceptibility, and enhances the energy efficiency and practicality of salt gradient power systems.
Implementation Method 1
separating, by a selectively permeable membrane, a first saline solution from a second saline solution
Implementation Method 2
transferring, by a heat pump, thermal energy to the first saline solution and/or the second saline solution
Implementation Method 3
capturing at least some salinity-gradient energy as electrical power
Implementation Method 4
capturing at least some salinity-gradient energy as electrical power
Implementation Method 5
heating the spent dilute solution to decompose the salt to make at least one gaseous product
Implementation Method 6
When the method includes generating the third saline solution by membrane distillation
Implementation Method 7
The method may include using a portion of the generated electrical power to produce hydrogen gas through electrolysis
Data Source
AI summary
A method and a system of generating electrical power or hydrogen from thermal energy is disclosed. The method includes separating, by a selectively permeable membrane, a first saline solution from a second saline solution, receiving, by the first saline solution and/or the second saline solution, thermal energy from a heat source, and mixing the first saline solution and the second saline solution in a controlled manner, capturing at least some salinity-gradient energy as electrical power as the salinity difference between the first saline solution and the second saline solution decreases. The method further includes transferring, by a heat pump, thermal energy from the first saline solution to the second saline solution, causing the salinity difference between the first saline solution and the second saline solution to increase. The method and system may include a regeneration process, such as membrane distillation, forward osmosis, electrodialysis, salt evaporation and/or salt decomposition for further energy efficiency and power generation.