The Microalgae Photobioreactor Feasibility Study and Industrial Scale-Up evaluated the technical, environmental, and economic feasibility of producing pharmaceutical-grade microalgae using industrial CO₂ emissions captured from the IPLOM oil refinery. The project aimed to reduce carbon dioxide emissions while developing a sustainable industrial process that exploits two locally available resources: purified CO₂ generated from the refinery’s steam reforming process and low-cost internally generated electricity.

The feasibility assessment was based on experimental data obtained from a 200 L pilot-scale closed cylindrical photobioreactor equipped with artificial lighting. Prometheus performed a comprehensive industrial scale-up analysis, including biomass productivity, CO₂ capture efficiency, nutrient and water consumption, mass and energy balances, capital investment (CAPEX), operating costs (OPEX), and overall economic performance. The analysis showed that scaling the original reactor configuration was not economically viable because of limited biomass productivity, high electricity consumption for artificial lighting, and insufficient product revenues.

To overcome these limitations, Prometheus developed an alternative industrial-scale solution based on twenty transparent tubular photobioreactors, each with a working volume of 8.5 m³, installed inside a high-transmittance greenhouse. The proposed facility is designed to produce approximately 5,000 kg of high-quality pharmaceutical-grade microalgae per year while significantly reducing energy consumption by maximizing the use of natural sunlight during daytime operations. Artificial LED lighting is activated only when solar irradiance is insufficient, substantially lowering operating costs.

The modular reactor configuration increases operational flexibility by allowing individual photobioreactor units to be isolated for maintenance or contamination control without interrupting the overall production process. The system integrates automated CO₂ injection, nutrient dosing, water recycling, and continuous monitoring of key process variables—including pH, dissolved oxygen, temperature, and biomass concentration—to maximize productivity while minimizing resource consumption.

Downstream processing includes biomass harvesting by centrifugation followed by drying to obtain a stable, high-purity microalgal powder suitable for pharmaceutical and high-value commercial applications. The study demonstrated that the redesigned greenhouse-based tubular photobioreactor system provides a technically feasible and economically viable solution for sustainable industrial microalgae production while contributing to carbon dioxide utilization and industrial decarbonization.