Microalgae is a promising source of biomass for generating diverse chemicals, fuels, and other materials. Among different routes to exploit the potential of microalgae, pyrolysis has gained continuous interest during the past decades. Pyrolysis is a thermochemical conversion process that operates at 300-800 °C in the absence or limited presence of oxygen. The main products obtained from microalgae pyrolysis are biochar, bio-oil, and non-condensable gaseous. The yield and properties of these products depend on process conditions, including temperature and residence time, and feedstock characteristics.
Biochar has unique chemical, physical and biological properties, which make it an attractive material for different applications. It has been considered a soil enhancer, improving fertility and mitigating desertification while reducing Greenhouse Gas emissions. Biochar is also a solution for carbon sequestration, taking it out of the short-term carbon cycle The microalgae carbon sequestration potential, through photosynthesis, can be further enhanced by pyrolyzing the microalgae and burying the produced biochar in the soil. In addition, biochar can be used as an additive in the anaerobic digestion of food waste and sludge, which play multifunctional roles to enhance yield and improve biogas quality under certain conditions.
In the ALGECO project, the microalgae biomasses will be pyrolyzed and the produced biochar will be characterized by combining different analytical techniques. The potential use of biochar in agriculture and as an additive for biogas production will be assessed.