Biochars produced from biomasses are an emerging type of renewable material that cannot only replace fossil-based coal but also perform as raw materials in high-value applications such as electronics. In the BRAGI project, we aim to develop sustainable and economically feasible methods to process and activate various biomasses into biochars to be used in future energy applications. The developed chars have different morphologies and heteroatoms depending on the used processing method and origin of the biomass. Hence, they can be suitable for a variety of energy application including photovoltaics and supercapacitors.
Main results
Hydrothermally carbonized and alkali-activated brewer's spent grain has a microporous structure leading to an extremely high surface area making it a promising candidate for electrochemical applications.
Dye solar cells with activated brewer's spent grain biocarbon performed well in extended accelerated aging test, and the biocarbon also reduced the degradation via loss of electrolyte charge carriers during the aging test.
Activated brewer's spent grain biocarbon provides a promising alternative for platinum-based catalysts.
Related publications
Tiihonen, A., Siipola, V., Lahtinen, K., Pajari, H., Widsten, P., Tamminen, T., Kallio, T., & Miettunen, K. (2021). Biocarbon from brewery residues as a counter electrode catalyst in dye solar cells. Electrochimica Acta, 368, [137583]. https://doi.org/10.1016/j.electacta.2020.137583
Al Haj, Y., Mousavihashemi, S., Robertson, D., Borghei, M., Pääkkönen, T., Rojas, O. J., Kontturi, E., Kallio, T., & Vapaavuori, J. (2022). Biowaste-derived electrode and electrolyte materials for flexible supercapacitors. Chemical Engineering Journal, 435(3), [135058]. https://doi.org/10.1016/j.cej.2022.135058