Overview
In order to combat human-caused climate change, in addition to reducing new CO2 emissions, it is neces-sary to use Negative Emission Technologies (NETs) on a global scale. One possible solution to remove CO2 from the atmosphere is through the production and storage of biomass. Microalgae produced in warm water are the most efficient way to produce biomass, as its growth rates are up to 50 times higher than fast-growing plants on land. Photobioreactors, which can be powered by both natural and artificial light, are used in this project to produce microalgae. With photobioreactors and pure CO2 as carbon source, costs are about 0.5 US$ per kilogram of dry biomass, which is equivalent to 0.3 US$ per separated kilo-gram of CO2. Research has shown that it is possible to produce biomass at a rate of 287 tons per hectare per year using photobioreactors.
The results from Reto Tamburini's Master thesis and a Life Cycle Analysis project have led to the conclu-sion that the production of microalgae in photobioreactors as a NET (Carbon Dioxide Removal) is envi-ronmentally beneficial if the process is powered mainly by natural light. This overall process including CO2 emissons for building the reactors and their disposal after 20 years, the provision of nutrients a.s.o. is CO2-negative, meaning it has a positive impact on the environment. If the process requires a higher demand for technical energy (artificial light, etc.), it is only environmentally meaningful if the generated biomass is used as a raw material to replace fossil raw materials in industrial processes, reducing CO2 emissions. This approach is referred to as Carbon Capture and Utilization (CCU). The goal of this project ist to pursue these two approaches with the goal of developing and operating photobioreactor systems on a large scale, both to directly remove CO2 from the atmosphere and to reduce CO2 emissions through the production of biogenic substances.
