Lipids extraction from wet Chlorella pyrenoidosa sludge using recycled [BMIM]Cl

Area of Science:

• Biotechnology
• Chemical Engineering
• Environmental Science

Background:

• Microalgae are a promising source for biofuels and biochemicals.
• Efficient cell disruption is crucial for extracting valuable compounds from microalgae.
• Ionic liquids (ILs) offer potential for microalgae pretreatment but their cost necessitates recycling.

Purpose of the Study:

• To evaluate the recycling efficacy of the ionic liquid [BMIM]Cl for microalgae (Chlorella pyrenoidosa) pretreatment.
• To assess the stability of the IL during the recycling process.
• To determine the energy consumption and solvent loss associated with IL recycling.

Main Methods:

• Pretreatment of Chlorella pyrenoidosa using the ionic liquid [BMIM]Cl.
• Lipid extraction using methanol followed by antisolvent precipitation for IL recovery.
• Chromatographic separation of IL from hydrolysates.

Main Results:

• The molecular structure of [BMIM]Cl remained stable throughout the recycling tests.
• Five cycles of antisolvent precipitation recovered 99.8% of the IL.
• The energy consumption for IL recovery was 4.46 MJ/kg dry microalgae.
• IL loss was minimal, below 1.97 µg/kg dry microalgae, using chromatography.

Conclusions:

• Ionic liquid [BMIM]Cl is a stable and highly recyclable solvent for microalgae cell disruption.
• Efficient recovery methods significantly reduce IL loss and energy requirements.
• This approach enhances the economic viability of using ILs in microalgae processing.