4. Environmental biorefineries

Environmental biorefineries (figure 6 ) are characterized by :

• focusing on plant fractions that cannot be consumed for human or animal consumption, or that have a low food value. They enable potential pollution to be treated;

• simplification of upstream technologies to simple grinding of agricultural or agro-industrial residues, or even dedicated energy crops in some countries;

• the presence of a main compartment involving biotechnological action, similar to a bioreactor.

The first family of environmental biorefineries covers methanization