Ultra low-pressure filtration system for energy efficient microalgae filtration.

Area of Science:

• Biotechnology
• Environmental Engineering
• Chemical Engineering

Background:

• Microalgae cultivation is increasing for various products.
• High energy demands for microalgae harvesting are a major challenge.
• Efficient harvesting methods are crucial for economic viability.

Purpose of the Study:

• To evaluate energy-efficient microalgae harvesting using ultra-low-pressure membrane (ULPM) filtration.
• To investigate the impact of aeration on ULPM performance and energy consumption.
• To determine optimal conditions for reducing energy input in microalgae harvesting.

Main Methods:

• Utilized ultra-low-pressure membrane (ULPM) filtration (<20 kPa) for microalgae harvesting.
• Compared systems with and without aeration to assess fouling control and permeability.
• Measured transmembrane pressure (TMP), clean water permeability, and specific energy consumption.

Main Results:

• Membrane compaction caused up to 66% permeability loss with increasing TMP (2.5 to 19 kPa).
• Aeration significantly improved broth permeability, reducing losses from 56% at low TMP.
• Specific energy consumption for ULPM was as low as 4.4 × 10^-3 kWh/m³.

Conclusions:

• ULPM filtration is an energy-efficient method for microalgae harvesting.
• Aeration effectively mitigates membrane fouling at low TMP, enhancing system performance.
• The combination of low TMP and aeration provides the most energy-efficient harvesting solution.