Lumped Kinetic Modeling of a Polyolefin Co-Pyrolysis Process

Plastics are often criticized because of their lack in recycling and their post-consumer transfer to non-EU jurisdiction. Therefore, the recycling rates must increase. Apart from eco-design and mechanical recycling, plastic pyrolysis is a promising process to close the hydrocarbon cycle. To reach this goal, a plastic co-pyrolysis process in tubular reactors was developed, which mixes a carrier medium to the plastic melt to reduce the viscosity, thus enhance the heat transfer. However, for upscaling a kinetic model for predicting the yields of the plastic pyrolysis in a tubular reactor is needed. For this reason, a pilot plant provides experimental data for the pyrolysis of different plastics and carrier media. Thus, a model in Matlab in combination with a commercial refinery simulation tool “Petro-SIM” is established. The reaction structure of the
model is formed by “Lumped Kinetic Modeling”, which groups the multiple species of hydrocarbons by their boiling cut and makes the reaction scheme manageable.
Furthermore, the heat transfer and required endothermic reaction heat are
implemented into the model to predict the experimental data properly. Accordingly, reaction rates are determined and a scalable plant simulation can be developed.