Microwave-Assisted Pyrolysis Process: From a Laboratory Scale to an Industrial Plant

One of the great challenges for the European Union (EU) is the “Circular Economy Package,” and to achieve this goal, materials at the end of their life cycle must be recycled using a sustainable process. In this way, as a thermochemical treatment, pyrolysis represents a significant opportunity so long it leads to the recovery of both energy and chemical content of mixed, contaminated, or deteriorated plastics. An excellent history of an academic-industrial adventure started in 2008 at the Department of Chemistry of the University of Florence demonstrates the possibility of employing microwaves to recycle plastics to preserve their energy and chemical content. After that, Techwave started industrialization of the process in 2019, realizing a small-scale prototype followed by a full-scale pilot plant using different plastic materials (e.g., polystyrene, acrylonitrile-butadiene-styrene (ABS), and polypropylene). Nowadays, the plant may process 90 kg/h of plastics with a low formation of char and gas and an interesting amount of liquid useful as a source of chemicals or fuel because it has an LHV of 35–43 kJ/kg. The Microwave-Assisted Pyrolysis (MAP) is an industrial novelty in plastic recycling, and it looks very promising for a much more modern and innovative plastic waste recovery system.