4. Pyrolysis

4.1 Thermal process

Pyrolysis (or thermolysis) is the thermal dissociation of organic and mineral matter, in the absence of oxygen (less than 2%), under the action of heat (400 to 800°C). It is therefore a non-combustion, endothermic thermal treatment. Depending on reaction conditions (temperature, oxygen partial pressure, total pressure), the organic fraction breaks down into gases, oils and solid carbonaceous residues. Low temperatures favor oil production over gas (figure 9 ). These by-products will be recovered at the end of the process, with a view to being recycled [3] .

The low oxygen content...