Densification is a process which involves compressing the biomass mainly to improve its energy density and its homogeneity.
The biomass is usually grinded into fine particles, which will then be dried, if the moisture content is too high. The crushing thus obtained is compressed into a denser and more cohesive material. No chemical additive is used (natural additives such as starch might be used in limited quantity), the cohesion is ensured by the natural binders of the biomass.
Depending on the process used, pellets (6 to 8 mm diameter) or briquettes (>25mm diameter) will be produced.
Densification allows the increase of the energy content of the fuel per volume unit, therefore making its transport and storage more efficient. The densification process also has the advantage of converting a relatively heterogeneous fuel into a homogeneous and standardised product, enabling complete automation of the energy production installations (stoves, boilers).