Salt Recovery Solution for Zero Liquid Discharge
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Solution Overview
Problem
Current zero liquid discharge (ZLD) systems for salt recovery from aqueous solutions are energy-intensive and costly, limiting their economic viability, especially when dealing with high salinity feedwaters.
Innovation Solution
A salt recovery solution comprising specific combinations of C4-C9 ether, C3-C9 alkyl, C4-C9 ketone, and C3-C9 ester compounds that are immiscible with sodium chloride solutions, allowing for the precipitation of salt and concentration of brine without the need for membrane-based technologies, facilitating a non-osmotic and non-membrane process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal evaporation processes are used for salt recovery, then salt can be recovered from aqueous solutions, but energy consumption and operational costs increase significantly
Solution Approach 1:
The patent changes the fundamental parameter of the separation mechanism from thermal-driven (evaporation) to chemical-driven (complexation extraction). By using metal complexing agents that form insoluble complexes with salt ions at ambient conditions, the process eliminates the need for high-energy thermal evaporation while maintaining effective salt recovery from aqueous solutions
Solution Approach 2:
The patent replaces the mechanical/thermal system (evaporation and crystallization equipment) with a chemical system (complexation reaction and liquid-liquid extraction). This substitution uses chemical affinity between metal complexing agents and salt ions to achieve separation without mechanical energy input for phase change
2Use of energy by moving object
If reverse osmosis is used to concentrate brine, then energy efficiency improves compared to thermal evaporation, but the technology can only handle limited salinity ranges
Solution Approach 1:
The patent changes the operating parameter range by using chemical complexation that is effective across all salinity concentrations. Unlike reverse osmosis which relies on pressure differentials that diminish at high salinities, the complexation reaction proceeds effectively regardless of initial salt concentration, enabling treatment of both dilute and highly concentrated brines
Solution Approach 2:
The patent creates a universal salt recovery method that can handle various salinity levels and different types of aqueous waste streams. The metal complexing agents can selectively bind to different cations (Na+, K+, Ca2+, Mg2+), making the process adaptable to diverse feed compositions beyond just chloride salts
3Quantity of substance
If electrodialysis or forward osmosis are used for high salinity feedwaters, then concentration capability improves beyond reverse osmosis, but device complexity and capital costs increase
Solution Approach 1:
The patent extracts the salt ions from the aqueous phase into an organic phase through complexation extraction. This simple two-phase separation eliminates the need for complex membrane stacks, electrode assemblies, or pressure management systems required by electrodialysis and forward osmosis, achieving high concentration capability with minimal equipment
Solution Approach 2:
The patent uses relatively inexpensive metal complexing agents that can be readily synthesized or obtained. The organic solvent system can be regenerated and reused, and the process requires no expensive specialized membranes or electrical infrastructure, reducing both capital and operational costs
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 salt recovery and water concentration, achieving zero liquid discharge with reduced energy consumption and operational costs, making it a viable alternative for industrial brines with high salinity.
Implementation Method 1
adding the salt containing aqueous solution to a salt recovery solution; and allowing water from the salt containing aqueous solution to pass into the salt recovery solution
Implementation Method 2
at least one component of the salt recovery solution is substantially immiscible with an aqueous solution of sodium chloride
Data Source
AI summary
The present invention relates to a salt recovery solution and to a process for separating a salt from an aqueous solution. The present disclosure also relates to a salt recovery solution and to its use to concentrate a salt or brine solution by recovering water therefrom. The salt recovery solution comprising at least two or more components independently selected from any combination of integers a), b), c) and d): where a) is a straight, branched or optionally substituted cyclic C4-C9 ether containing compound; b) is a straight chain or branched C3-C9 alkyl substituted by —OH; c) is a straight chain, branched or cyclic C4-C9 ketone or C4-C9 diketone; and d) is a straight chain or branched C3-C9 ester containing compound.