Hybrid Salinity Gradient Power Generation for RO Brine Recovery
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Solution Overview
Problem
Current desalination processes using reverse osmosis are energy-intensive and generate high-concentration saltwater waste, which poses environmental risks and high energy costs, necessitating the development of more efficient and environmentally friendly systems for freshwater production and waste management.
Innovation Solution
A salinity gradient and solar energy hybrid power generation apparatus that integrates solar photovoltaic and thermal power generation with reverse electrodialysis and pressure retarded osmosis systems, utilizing ion exchange membranes and ion filters to efficiently produce electricity and reduce saltwater concentration, while also reusing and recycling water for further energy generation and microalgae cultivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If reverse osmosis process is used for desalination, then freshwater production is achieved, but energy consumption increases to 3-5 kWh/m³
Solution Approach 1:
The patent combines reverse osmosis desalination with salinity gradient power generation in a hybrid system where the high-concentration brine from RO is used as feed for RED/PRO power generation, and the produced electricity is fed back to power the RO process, thereby reducing external energy consumption
Solution Approach 2:
The patent converts the harmful high-concentration brine waste stream from RO into a valuable resource by using it as feed for salinity gradient power generation, transforming an environmental liability into an energy production opportunity
2Quantity of substance
If reverse osmosis process is used for desalination, then freshwater is produced, but high-concentration saltwater waste is generated causing environmental impact
Solution Approach 1:
Instead of discarding the high-concentration brine as waste, the system recovers it and uses it as feed for salinity gradient power generation, thereby eliminating the environmental disposal problem while generating additional value
Solution Approach 2:
The harmful concentrated brine waste is converted into a beneficial resource for power generation through RED or PRO processes, transforming an environmental hazard into an energy source
3Productivity
If salinity gradient power generation is combined with solar energy power generation, then electricity production efficiency increases, but device complexity increases
Solution Approach 1:
The patent merges solar photovoltaic/thermal power generation with salinity gradient power generation into a hybrid system that shares common infrastructure such as heat exchangers, piping networks, and control systems, thereby managing complexity while achieving synergistic energy production
Solution Approach 2:
The system employs multi-functional components that serve multiple purposes: solar collectors provide both thermal energy and photovoltaic electricity, heat exchangers serve both cooling and heating functions, and the brine stream serves both RO reject and RED/PRO feed functions
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 hybrid system enhances energy efficiency, reduces energy consumption in desalination, minimizes environmental impact by lowering saltwater concentration, and optimizes power generation while providing a sustainable method for freshwater production and waste management.
Implementation Method 1
ions pass through ion exchange membranes (a cation exchange membrane and an anion exchange membrane) due to a concentration difference between salinity contained in seawater and salinity contained in freshwater
Implementation Method 2
Electrical energy is generated through an oxidation-reduction (redox) reaction on the electrodes
Implementation Method 3
Pressure retarded osmosis (PRO) is a process of generating electrical energy using fluid pressure energy that is generated along with an increase in flow toward the seawater
Implementation Method 4
solar thermal power generation is a scheme of heating water or air with solar thermal energy and using the heated water or air for heating or hot water
Implementation Method 5
solar photovoltaic power generation is a renewable energy scheme of converting solar energy into electrical energy using a solar cell panel
Implementation Method 6
a salinity gradient power generation unit supplied with first saltwater and the first freshwater raised in temperature due to heat exchange with the solar photovoltaic power generation and/or solar thermal power generation unit
Data Source
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AI summary
The present invention provides a salinity gradient/solar energy hybrid power generation apparatus comprising: a photovoltaic power generation and/or solar thermal power generation unit which is supplied with first freshwater as cooling water; and a salinity gradient power generation unit which is supplied with the first freshwater having an increased temperature due to heat exchange with the photovoltaic power generation and/or solar thermal power generation unit and first saltwater, so as to generate electricity by the salinity gradient between the first freshwater and the first saltwater.