Turning biomass tar into high-value bio-carbon
Biomass pyrolysis is considered a key technology in the development of renewable energy. Through pyrolysis, different types of biomass or waste materials can be converted into valuable biochar and pyrolysis gas. A major drawback, however, is that the process also produces bio-tar as a byproduct. The treatment of bio-tar has long been a barrier to further development of pyrolysis technologies.
Scientists at Shenyang Agricultural University in China reviewed all aspects of biomass pyrolysis and reached a striking conclusion. They argue that bio-tar, with the right process optimizations, does not need to be treated as waste but can instead be transformed into bio-carbon: a new material with high-value applications. Central to this are polymerization mechanisms, strategies to steer the process, and the potential applications. Oxygen-containing compounds—such as molecules with carbonyl groups and furan rings—play a key role. Their reactive, unsaturated bonds allow the molecules to break apart and reconnect during polymerization.
The study discusses several ways to influence this polymerization. Reaction conditions, such as temperature and pressure, strongly affect the yield of bio-carbon by changing the structure of the bio-tar and the reaction pathways. Additives can also improve the properties of the resulting bio-carbon, for example by enhancing strength or chemical stability.
Bio-carbon produced in this way is seen as a promising new carbon material, opening opportunities for advanced applications and for circular production routes that add value to residual biomass streams. This review thus provides a theoretical foundation for both improved bio-tar management and the development of innovative carbon materials.
The research was published in Biochar under the title Preparation of bio-carbon by polymerization of bio-tar: a critical review on mechanisms, processes, and applications.
