Recovery of plastic waste through its thermochemical degradation: a review

The demand to produce plastic has increased yearly; only in 2020, there was a production of approximately 368 million tons worldwide. According to Plastics Europe, from 2016 to 2018, a total of 29.1 Mt of plastic waste was generated, and 24% of this ended up in a landfill, generating problems due to accumulation. The increase in the demand for plastics has begun to contribute to the shortage of oil sources, a non-renewable resource. On the other hand, various researchers have reported effects on human health such as neurological damage, cancer in the nasal cavities, prostate, and ovarian cancer, and in animal species, destruction of the digestive and respiratory tracts due to the consumption of microplastics in food. Due to these reasons, various solutions have been proposed for recovering and recycling plastic waste. One of the most promising technologies is thermal and catalytic degradation, known as pyrolysis. This technology allows the recovery of chemical compounds of high energy value. In this work, the various environmental and social impacts caused by plastic are discussed. Worldwide consumption data is provided by sector and type of plastic, and the different routes of thermal degradation for each type of thermoplastic are shown.