HDPE chemical recycling promoted by phenol solvent

The thermal cracking of HDPE in the presence of different amounts of phenol has been studied and compared with the reaction carried out without this solvent. HDPE conversion is enhanced with the amount of solvent, reaching a value of nearly 100% using a 1/10 HDPE/phenol ratio. The yield of the gaseous hydrocarbons also rose with the amount of phenol, olefins being the main products in this fraction. In all reactions, the main products of the C5–C32 fraction were linear hydrocarbons such as n-paraffins and α-olefins. The yields of both hydrocarbons increased in line with the amount of phenol. However, the increase was more significant in the case of α-olefins. All these results indicate that the phenol promotes the plastic degradation, enhancing the HDPE conversion and facilitating the formation of specific products. A reaction mechanism is proposed to explain these results, indicating random scissions and chain reactions which are favoured by the presence of this solvent during the HDPE thermal degradation.