Eutectic solvents with tuneable hydrophobicity: lipid dissolution and recovery

Area of Science:

• Green Chemistry
• Solvent Engineering
• Biorefining

Background:

• Eutectic solvents offer advantages but face challenges in product recovery.
• Existing methods for lipid recovery from hydrophobic eutectic solvents require additional chemicals and purification steps.
• Developing efficient and clean extraction methods is crucial for sustainable biorefining.

Purpose of the Study:

• To develop a novel, chemical-free approach for oil recovery from semi-hydrophobic eutectic solvents.
• To demonstrate tuneable hydrophobicity of a mixed imidazole-hexanoic acid solvent system.
• To achieve efficient phase separation and high purity oil recovery.

Main Methods:

• Formulation of a semi-hydrophobic eutectic solvent using imidazole and hexanoic acid.
• Solvatochromic analysis to determine tuneable hydrophobicity (dipolarity, π*).
• Induction of phase split by adjusting solvent composition (imidazole content) for oil recovery.

Main Results:

• The imidazole-hexanoic acid solvent exhibited tuneable hydrophobicity based on composition.
• The solvent effectively dissolved sunflower oil and algae oil at low imidazole concentrations.
• Addition of imidazole induced phase separation, yielding an oil-rich phase and a solvent-rich phase.
• Achieved ~75% recovery efficiency for both oils, with ~100% purity for sunflower oil and 86% for algae oil.

Conclusions:

• The proposed method offers an efficient and clean approach for oil recovery from eutectic solvents.
• Tuneable hydrophobicity of semi-hydrophobic solvents provides a viable strategy for product separation.
• This technique eliminates the need for additional chemicals, enhancing sustainability in oil extraction processes.