Theoretical prediction of product distribution of the pyrolysis of high density polyethylene

The main objective of this work is the formulation and development of a model that predicts the product distribution obtained in the pyrolysis of polyethylene. In order to do this a mechanistic model has been developed based on a radical mechanism. This model uses a small number of elementary kinetic steps, including initiation, β-scission, H-abstraction, aromatization and radical combination. The mechanism allows the prediction of the compounds obtained during the pyrolysis. Given the great number of species considered, the simulation of the pyrolysis process requires the solution of complex systems of ordinary differential equations. The results obtained have been validated with experimental results obtained in a free fall installation in which the pyrolysis process has been studied at different temperatures (500–1000 °C) and residence times (0.52–2.07 s).