Abstract
The valorisation of heterogeneous waste streams represents a key challenge for the transition towards circular and sustainable energy systems. Among these, mixtures of plastic and lignocellulosic residues are particularly relevant due to their high energy content and widespread availability. Microwave-assisted pyrolysis (MAP) has emerged as a promising alternative to conventional thermal technologies, offering rapid and volumetric heating, although its industrial application remains limited. In this work, an integrated modelling framework for the microwave-assisted co-pyrolysis of plastic waste and biomass is developed based on experimental data. A representative mixture (70 wt% plastic and 30 wt% biomass, dry basis) is used to simulate a small-scale industrial plant designed according to a short supply chain approach. The system includes drying, microwave pyrolysis, condensation, char gasification and combined heat and power generation. The model is scaled to a dry feed rate of 846 kg/h, corresponding to a syngas production of approximately 200 kg/h with a lower heating value of about 30 MJ/kg. The resulting energy flow enables the generation of 0.81 MW? of net electrical power, corresponding to an electrical efficiency of approximately 48 % relative to the syngas energy, while the overall conversion efficiency from feedstock to syngas is about 25 %. The results demonstrate that the proposed configuration can achieve full thermal self-sufficiency, through effective internal heat recovery. In addition, the integration of char gasification enhances overall energy efficiency and reduces solid residues. The study provides a structured approach for the scale-up of MAP systems and supports their potential role in decentralised waste-to-energy applications.
