Green Solutions for Urban Sustainability: Photobioreactors for Algae Cultivation on Façades and Artificial Trees

Abstract

The accumulation of CO2 in the atmosphere carries with it severe consequences, and cities are responsible for 70% of CO2 emissions. With this initiative, we address how innovative green architecture can contribute to removing CO2 from the urban area by implementing elements that incorporate microalgae cultivation into architecture. The presented project incorporates two photobioreactor installations filled with water, where microalgae circulate through methacrylate tubes. Used as two architectural elements: a façade that can fix 720 kg of CO2 per year from the atmosphere and produce 400 kg of biomass that can be used as fertilizer in irrigation water; and three artificial trees that can fix 50 kg of CO2 and produce 28 kg of biomass. To test its efficiency, a Life Cycle Inventory was conducted and compared to the amount of CO2 fixed during its lifetime. It was concluded that the system would need 11.11 years to fix the CO2 produced and would have a negative CO2 impact of 27 tons of CO2 during the useful life of its materials. This project is a starting point towards developing a disruptive and experimental alternative with great potential, being the first in Spain and one of the first in the world.