High efficiency microalgae production systems are designed to provide optimum growing conditions for the microalga of choice and development of downstream products. In essence, a photobioreactor system aims to provide optimal ‘artificial leaf’ conditions for the cells in solution. It must supply light, CO2 and nutrients, release O2 and heat and facilitate the removal of waste products.
The following key variables must be optimised to achieve best practice high efficiency systems.
Light delivery: Microalgae have a preferred range of illumination conditions. Advanced microalgae production systems are designed to deliver light in this range at the most cost competitive price.
CO2: The photosynthetic machinery captures solar energy and uses it to reduce CO2 to carbohydrates (CHO), hydrocarbons (CH) and a range of other biomolecules. Consequently efficient and cost effective CO2 supply to the microalgae cells is central to high efficiency processes.
Nutrients: Optimum biomass production requires optimum nutrient supply and delivery. Optimum nutrient supply and systems for their controlled delivery are essential for enhanced microalgae production.
Energy: Mixing can be an energy intensive process. High efficiency systems therefore require innovative solutions to minimise mixing.
Temperature: Microalgae typically grow within a defined temperature range. High efficiency systems therefore require the ability to control temperature and ideally minimise evaporative losses.
Recycling: For maximum sustainability systems require the integration of recycling of nutrients, water and CO2.