Crown Ether Lithium Extractant Compounds for Brine Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for extracting lithium from aqueous solutions, such as terrestrial and geothermal brines, are energy-intensive, time-consuming, and inefficient, often requiring thermal or solar evaporation and suffer from contamination issues due to the mixing of loading and regeneration streams in sorbent-based systems.
Innovation Solution
Development of novel lithium extractant compounds with specific coordinating functional groups and hydrocarbon chains that selectively chelate lithium ions and transport them into a hydrophobic phase, bypassing the need for thermal evaporation and sorbent methods by using a hydrophobic solvent system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If thermal or solar evaporation is used to extract lithium from brines, then lithium can be concentrated and produced as a final salt product, but the process requires 18-24 months and consumes large amounts of energy
Solution Approach 1:
The patent changes the chemical parameters of the extraction system by introducing selective crown ether extractants that form stable complexes with lithium ions. This allows lithium to be extracted at room temperature through liquid-liquid extraction, eliminating the need for thermal evaporation and reducing extraction time from years to hours while maintaining energy efficiency
Solution Approach 2:
The patent replaces the mechanical/thermal evaporation system with a chemical extraction system using crown ethers. The extractants selectively bind lithium ions in the brine solution and transfer them to an organic phase, achieving rapid separation without thermal energy input or prolonged evaporation processes
2Reliability
If packed columns with layered lithium aluminates are used for lithium recovery, then lithium can be selectively extracted, but the sorbent particles deteriorate and crystal structures collapse over time, shortening their lifetime
Solution Approach 1:
The patent replaces the solid sorbent packed column system with a liquid-liquid extraction system using crown ether extractants dissolved in an organic solvent. This eliminates the mechanical stress and structural degradation that plague solid sorbent particles, while maintaining high lithium selectivity through the chemical specificity of crown ether-lithium complexation
Solution Approach 2:
The patent uses composite crown ether molecules that combine the selective lithium-binding capability of cyclic ethers with hydrophobic tail groups. This composite structure allows the extractant to selectively complex lithium ions while remaining soluble in the organic phase, achieving both high selectivity and operational stability without the degradation issues of solid sorbents
3Productivity
If packed columns are used for lithium extraction, then lithium can be recovered from aqueous solutions, but loading and regeneration streams mix, contaminating even the most selective sorbent materials
Solution Approach 1:
The patent segments the extraction process into distinct liquid phases (aqueous feed and organic extractant phases) that can be separated after contact. This phase separation allows the loaded organic phase to be independently processed for lithium recovery without mixing with the regeneration stream, preventing contamination and maintaining product purity while enabling continuous operation
Solution Approach 2:
The patent uses the organic solvent phase as an intermediary carrier that temporarily holds the lithium-crown ether complex. This intermediary phase allows lithium to be transferred from the aqueous feed without direct contact between loading and regeneration streams, preventing contamination while maintaining continuous process operation through phase separation
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
The process achieves efficient and selective lithium extraction from aqueous solutions, even in the presence of high concentrations of other ions like sodium and potassium, with improved cost-effectiveness and reduced environmental impact.
Implementation Method 1
The lithium extractant compounds possess precisely or at least two coordinating functional groups, typically selected from carbonyl, hydroxy, amine oxide, and combinations thereof
Implementation Method 2
at least one or two hydrocarbon groups containing 1-30 carbon atoms to confer a hydrophobic property
Data Source
AI summary
Lithium extractant compounds having the following structure:wherein: Ra and Rb are independently selected from the group consisting of hydrocarbon groups (R), —OR, —NRR′, —SR, —SO2R, —SO2NR2, —C(O)R, —C(O)OR, —C(O)NRR′, —C(S)OR, —C(O)SR, and —C(S)NRR′; R′ is selected from R′ groups, wherein R′ is selected from H and R groups; X is O or OH; Y is C or N, wherein, when Y is N, then Ra is R. Also described are hydrophobic water-insoluble solutions containing at least one extractant compound of Formula (1). Also described is a method for extracting lithium from an aqueous solution by contacting the aqueous solution with the hydrophobic solution, and optional stripping of lithium from the hydrophobic solution by contacting the hydrophobic solution with an aqueous stripping solution.