The aim of the torrefaction processes is the processing of biomass (wood chips, green waste, grasses etc.) into a solid, easily transportable and storable fuel with the highest possible energy density. Biomass is submitted to a mild pyrolysis, i.e. it is roasted at approx. 300°C under the exclusion of air. In this process, certain components of the raw material are converted into gas. This gas is used for energy generation in the torrefaction plant while the raw material’s remaining solid main component is processed into a highly compressed briquette..

Since 2010, Polytechnik has been part of a consortium for the development of a massively scalable process for the torrefaction of biomass. The aim was to develop a combined biomass/gas firing which, in addition to the solid fuel, also used the lean gas, which develops during the torrefaction. We developed a combustion unit which facilitates a particularly high energy yield as well as a complete combustion of the lean gas. In this way, a process could be developed which harnesses almost all of the necessary heat energy from the process sequence itself.