Microalgae that convert sunlight energy into biomass

The CO2Algaefix project, aimed at valorizing carbon dioxide through microalgae cultivation, has concluded after four years of research and development. This ambitious project, co-financed by the EurUnion's Directorate-General for the Environment through the LIFE+ program, was launched to demonstrate the viability of a CO2 capture and biofixation process using microalgae in an industrial power generation plant. Filipa Ferrao, the EurCommission's Monitor Team member for the CO2Algaefix project, made the final visit to the microalgae cultivation plant located in Arcos de la Frontera, Cádiz, where she was able to observe the actual implementation of the prototype, as well as the numerous technical and economic advancements achieved. Filipa Ferrao noted that "everything learned over these four years, including the mistakes, is important, as it will serve to improve the current state of the art and ensure the continued operation of this facility, and others like it.".

The CO2Algaefix project has involved the construction and operation of a pre-industrial scale microalgae cultivation plant in Arcos de la Frontera, an area with high levels of solar radiation and temperatures that favor the cultivation of these photosynthetic microorganisms, using as a carbon source the combustion gases from the Iberdrola Combined Cycle Power Plant (1,600 MW of installed capacity), adjacent to the plant.

100 tons of biomass per hectare per year
The construction and operation of this plant has been a milestone worldwide, due to its dimensions, the cultivation techniques applied and the technical-scientific objectives pursued, among which are achieving a production of 100 tons of biomass per hectare per year, equivalent to the capture of 200 tons of CO2 per hectare per year.

Microalgae are photosynthetic organisms capable of converting sunlight energy into biomass with high efficiency, consuming carbon dioxide as their primary nutrient and releasing oxygen into the atmosphere. This allows for the mitigation of greenhouse gas emissions while yielding a wide variety of products with applications in diverse sectors, including agriculture, nutraceuticals, cosmetics, and aquaculture, among others.

World's first pre-industrial scale installation
The CO2Algaefix project's microalgae cultivation plant has been the world's first pre-industrial scale installation to implement various cultivation techniques, tubular reactors, flat vertical reactors and raceway reactors, on a pre-industrial scale, and using industrial flue gases as a carbon source for the crops.

The idea of ​​installing different cultivation technologies arose with the aim of comparing the achievable productivity rates, in terms of biomass production and CO2 fixation, as well as having a versatile facility capable of cultivating a wide range of strains and with different construction and production costs.

In this regard, the Monitor Team highlighted during the visit the importance of all the knowledge and valuable experiences acquired over the 4-year period in which the project has been developed, including the mistakes, from which very relevant information has been obtained that has served to improve the state of the art and that will allow the continuity of the operation of this plant, and of others that may be built in the future, with criteria of efficiency.

With this objective, the results obtained and experience gained from this project, as well as the aspects to consider when setting up and operating an industrial facility for cultivating photosynthetic microorganisms (microalgae and/or cyanobacteria), are made available to researchers, companies, and Practices Manual . Published by the partners of CO2Algaefix, it can be accessed through this website .