Cost-effective and sustainable microalgae cultivation: A low-cost artificially integrated LED photobioreactor ensuring high-quality algal biomass production from industrial CO2 flue gas in a high latitude country

The equipment required for large-scale production of quality microalgal biomass is costly to set-up. To address this challenge a novel low-cost internally illuminated reactor ‘the Cube’ has been developed, which is suitable for deployment in high latitude countries with low natural light conditions. This innovative concept combines the use of low-cost materials, LED lighting, effective temperature and pH control technology to produce high quality algal biomass from industrial CO 2 effluent at low initial capital cost. This study evaluated the ability of the cube by growing Arthrospira platensis (Spirulina). The reactor achieved biomass concentrations of 1.37 g L -1 and 80.5 mg L -1 day -1 productivity in a 1 m 3 volume that occupies 1 m 2 , with consistent productivity spanning 78 days, surpassing some of the existing most cost-effective microalgae cultivation system designs currently available. Aerial productivity was demonstrated as 92.1 kg year -1 m -2 compared to 4.2 kg year -1 m -2 for a comparable raceway. Protein composition was 54.1% and phycocyanin content was 78.27 mg g -1 of biomass. An economic appraisal gave capital cost as £12,776.60 per m 3 reactor and potential profits from pigment and protein production lead to a payback period of only 1.7 years. This novel reactor demonstrates sustainable profits from carbon capture and reuse.