**2.1 Preliminary studies of MAP process**

Techwave s.r.l. is an Italian start-up established to realize an industrial plant from a patent able to transform, by means of microwave, plastic complex polymers into their original components, ready for a new use. The process is based on an Italian proprietary patent [21] of Cooperativa Autotrasportatori Fiorentini (CAF Scrl-Italy) developed and filed by a research team of Department of Organic Chemistry – University of Florence – Italy, in 2011, and converted into a European patent [3] acquired by Techwave in 2018.

Experiments were started in 2008 at the Department of Organic Chemistry "Ugo Schiff," University of Florence, where a set of trials were performed on tires and various types of plastic materials, ranging from polystyrene (PS) to polyethylene (PE), polypropylene (PP), poly(ethylene terephthalate) (PET), poly(vinyl chloride) (PVC), and their mixtures [22]. Similar experiments were also performed on Waste Electric and Electronic Equipment (WEEE) [18].

Pyrolysis studies were initially performed on a laboratory scale (**Figure 2**). The experiments were carried out on a batch oven, and 100–300 g/h of materials were processed. The oven was equipped with four external MW generators, each having an absorption of electric power of 2 KW capable of delivering up to 6 KW of microwave power inside the oven, operating at the frequency of 2.45 GHz.

During the experimental trial, many arrangements were tested to determine the influence of several parameters on the quantity and quality of the three products formed: a liquid, an uncondensable gas, and a char. In particular, it was verified how some critical factors such as the residence time inside the pyrolytic oven, the temperature reached, and the type of downstream fractionating system would affect the amount and the composition of the three products of the reaction. The liquid may be employed for the synthesis of new polymeric products (**Figure 3**), while the gas and char may be used as fuel or employed for other uses [1].

This first study showed MAP as a suitable technique for cracking various types of plastic even if they may be highly contaminated and absolutely heterogeneous. The results obtained led to the publication of various scientific papers and process patents

**Figure 2.** *Laboratory MW oven.*

**Figure 3.** *The circular economy using a MAP process for polymeric waste materials.*

(**Table 2**) and the identification of the guidelines for the scale-up of MAP technology to an industrial level [1].
