Hydrothermal carbonisation (HTC) of biomass is a thermo-chemical process for the conversion of solid biomass matter at elevated temperature and pressure in the presence of water. The resulting product is a coal-water-slurry. The coal fraction can easily be separated and differs significantly in its chemical and physical properties from the starting material.
During the HTC reaction, water, carbon dioxide and other compounds are cleaved from the biomass. Thereby the energy density is raised significantly and the heating value is approximate to that of dry, high quality brown coal. At the same time, the macromolecular structure of the original biomass will be largely to completely destroyed. This provides a porous, brittle and in part dust-like product that is considerably easier to dry and to convert to electricity, heat or fuel than the origin biomass. This is a clear conceptual advantage for energy use compared to, for example, the burning or gasification of untreated biomass.
Given that hydrothermal carbonisation takes place in an aqueous reaction medium, damp biomass can be utilised and indeed is even preferred. Such biomass materials are currently not or are barely used since the competition on utilisation is minimal. Competition on food and animal feed does not exist either for most of the relevant biomass substrates with high moisture content. HTC rather can be seen as a complementary approach to already established concepts withing the framework of integrated biorefineries and indeed, distinct synergy effects in this context are expected.
The process will be technically implemented by the project partner SunCoal Industries.